However, the truck-shop was gradually disappearing. Every year it became easier to expose evasions, and in good times the workers used their prosperity to slip away from the Company store. In 1850 a final campaign was initiated by five local Anti-Truck Associations, backed by the National Miners' Association under Alexander MacDonald. Truck-masters were prosecuted and truck was steadily dislodged from the coalfields and adjacent ironworks. Only in the nail trade did it survive, for the reason that the complete subjection of the nailers made it possible to practise the essentials of truck without a formal violation of the law.

In the remaining colliery districts in 1871 truck was prevalent only in West Scotland and South Wales.

In West Scotland it was yielding ground before the pressure of the unions. The companies only maintained it by active coercion. If a miner held out for money, they had to yield; and if they were malicious, they marked him as a sloper and dismissed him the first when a depression came. 'Black lists', said the Truck Commissioners, 'are often kept of slopers; threats of dismissal were repeatedly proved; and cases of actual dismissal for not dealing at the store are not rare.'[63] However, the masters themselves were getting tired of it, since it led so frequently to strikes.

Truck in South Staffordshire was bound up with the butty system; in railway construction with the system of contracting and sub-contracting, and similarly in South Wales, as also in the west of Scotland, it was bound up with and dependent on the system of long pays. In order to carry on from one pay day to the next, the men got advances on the company's store. In this way many lived permanently ahead of their wages. The thriftless and drunkards were always 'advance men, but the provident miners hated it and only dealt there on compulsion'.

The Commissioners drew a vivid picture of Turn Book morning in South Wales at the close of the pay month.

At 1 or 2 a.m. the women and children begin to arrive with their Advance Books. Perhaps one hundred would be there, wet or fine, sleeping on the doorsteps or singing ballads until morning.

At 5.30 a.m. the doors opened, and the waiters made a rush for the counter. Advance Books were produced, and goods handed over up to the amount of wages which would shortly fall due. Women took their pick of the articles, groceries, tobacco, occasionally a few shillings.

'It is quite usual', say the Commissioners, 'for shoemakers and other small tradesmen in the neighbourhood of Abersychan to be paid by the workmen in goods.... Tobacco in several districts of South Wales has become nothing less than a circulating medium. It is bought by the men and resold by them for drink, and finds its way back again to some of the Company's shops. Packets of tobacco pass unopened from hand to hand. An Ebbw Vale grocer who took the Company's tobacco at a discount declared: "For years, when they were selling it for 1s. 4d. a lb. I used to give 1s.; but I was so much over-flooded with it that I was obliged to reduce the price to 11d. That would not do still, and I had to reduce it to 10d. I told the men to take it to some other shop if they could get 11d. or 1s. for it. I was obliged to do that many a time, in order to get rid of the large stocks I held in hand. Tobacco will not keep for many months without getting worse."'

Weekly pays, therefore, were the constant demand of the miners' unions. In Northumberland and Durham, whence truck had disappeared long ago, pays were fortnightly, and the only objection advanced by the owners against weekly pays was the practical inconvenience of the pressure on the pay staff. In the North of England Iron Trade, weekly pays, the Commissioners found, had just been introduced. In West Scotland some of the coal-owners were trying to recoup themselves for the loss of their truck-shop by charging poundage on the men's wages. But this dodge, like the bigger grievance of truck, was stoutly resisted by the local union. Indeed, in one coalfield after another the disappearance of truck and kindred evils coincides with the appearance of strong County Unions.

6. We are given to understand that the miners of South Wales insist on economics written by sound labour men. We therefore offer them a few suggestions for a history of the currency in the nineteenth century from the worker's point of view.

i. In 1800 London relied for small coin on private enterprise. Every week the Jews' boys collected from the shopkeepers their bad shillings, buying them at a heavy discount, with serviceable copper coin forged in Birmingham (vide Patrick Colquhoun, A Treatise on the Police of the Metropolis, 1800, Chapter VII). The resumption of cash payments in 1819 was injurious; for owing to the shortage of small coin, the wage-earners were paid in bulk with large notes, which they had to split at the nearest public-house. The Truck Act of 1831 prohibited wage-payments in notes on Banks more than 15 miles distant, but said nothing about cheques—an oversight which the capitalists repeated in their Bank Act of 1844.

ii. The general dissatisfaction with the state of the currency led to attempts to dispense with coin. About 1830 Labour Exchanges were opened in London for the exchange of goods against time notes, representing one or more hours of labour. The originator was Robert Owen, and the failure of the Exchanges was probably due to the fact that Owen was at heart a capitalist. The National Equitable Labour Exchange at one time was doing a business of over 20,000 hours per week, but very shortly after this, the President (Owen) had to report a serious deficiency of hours, many thousands having been mislaid or stolen. The Exchange in consequence had to close its doors.

iii. In the 'forties the centre of interest is the Midlands, and the period may be termed the Staffordshire or beer period. The currency was very popular and highly liquid, but it was issued to excess and difficult to store. More solid surrogates were therefore tried. A Bilston pawnbroker[64] said that he had in pawn numerous batches of flour, which the men's wives had brought from the Truck Shops and turned into money, in order to pay their house-rents. Flour, however, was not so hard as a Prescot watch.

iv. We come next to the Welsh or Tobacco period, when the currency was easily transferable, but liable to deterioration.

v. Finally, in the last quarter of the nineteenth century, the world of labour attained to a cash basis, and there was no Cobbett to denounce the resumption.

We shall not be guilty of serious exaggeration if we preface our history with the motto:

'In the nineteenth century the Trade Unions and the Trade Unions alone made the nominal earnings of the working man a cash reality.'

3. THE SPIRIT OF ASSOCIATION

1. The student of Dicey's Law and Opinion in England is invited to distinguish three periods:

i. The period of old Toryism or legislative quiescence (1800-38).

ii. The period of Benthamism or individualism (1825-70).

iii. The period of collectivism (1865-1900).

Bentham lived during the first period and his name is rightly given to the second period.

The student, therefore, comes to wonder if there is anything which is not Benthamism. Benthamism, he says to himself, stands for individualism. How then can the period of Benthamism include the humanitarian legislation which begins with the first Factory Act of 1802 and broadens out during the middle of the century into the elaborate code regulating from then onwards the conditions of employment in workshops, factories, and mines? How can a monster beget an angel?

We may perhaps throw light on this difficulty by suggesting that the social trend from 1825-70 cannot be compressed into a single word. Individualism may suffice to define the dominant legal trend, but it conceals the influence exerted on the legislature from without and from below by the action of voluntary associations. The period of voluntary association coincides with and overlaps the period of individualism.

2. What Bentham was to individualism, Robert Owen was to voluntary association. Bentham himself was an admirer of Owen and supported his philanthropy, but, as expressions of a social attitude, Benthamism and Owenism were poles asunder. The contrast between the two is admirably displayed in the evidence given before the Factory Committee of 1816 by two representatives of the employing class, Josiah Wedgwood of pottery fame and Robert Owen himself.

'In the state of society,' said Wedgwood, 'in which there is evidently a progressive movement, it is much better to leave things as they are than to attempt to amend the general state of things in detail. The only safe way of securing the comfort of any people is to leave them at liberty to make the best use of their time, and to allow them to appropriate their earnings in such way as they think fit.'[65]

Robert Owen thought otherwise. In a couple of answers he exposed the fallacy of enlightened self-interest. They seem obvious enough to-day, but in 1816 they were the voice of one crying in the wilderness. He was asked whether he believed that 'there is that want of affection and feeling on the part of parents, that would induce them to exact from their children more labour than they could perform without injury to their health;' and he replied:

'I do not imagine that there is the smallest difference between the general affection of the lower order of the people, except with regard to that which may be produced by the different circumstances in which they are placed.'[66]

Another question was: 'Do you conceive that it is not injurious to the manufacturer to hazard, by overwork, the health of the people so employed?' He replied:

'If those persons were purchased by the manufacturers I should say decisively, yes; but as they are not purchased by the manufacturer and the country must bear all the loss of their strength and their energy{;} it does not appear, at first sight, to be the interest of the manufacturer to do so.'[67]

Owen had grasped the meaning of social responsibility, and he devoted his life to social service. But he was too wayward to observe the conventions of society, and passed beyond the social pale. The factory reformer became the Socialist. Whether his disciples comprehended his philosophy we may doubt, but he understood better than any one else their instinct for association, and he gratified it.

It is not contended that Owen was responsible for all the associative effort of his generation; for with political and religious associations he had no sympathy. But the spirit which infected him infected others after him, rousing them to associate now for this, and now for that social or religious or political purpose.

3. We may divide associations for social purposes into two classes.

To the first class belong associations formed to secure the abolition of some abuse. These naturally disappear when their object is attained.

For example, there was the Anti-slavery Campaign in which Joseph Sturge and other Quakers played so prominent a part. By an organized crusade of political education the Abolitionists induced an originally hostile Parliament to emancipate the West Indian negroes in 1833, and to shorten the period of semi-servile apprenticeship in 1838. Yorkshire was the home of the Short Time Committees, which organized the campaign against White Slavery at home. The Ten Hours Movement caused the Ten Hours Bill to become the law of the land. From Lancashire came the Anti-Corn Law League, whose story is told in another chapter.

The second class of association was the association for economic betterment—the Friendly Society, the Co-operative Society, the Trade Union. Conceived in enthusiasm and self-inspired, these associations asked only of the State a legal framework in which to develop, but they did not win it without struggle and delay.

The Government was anxious to encourage thrift, but the development of the Friendly Societies was impeded for a time by legislation aimed at political conspiracy. The Corresponding Societies Act of 1799 prevented the Friendly Societies from forming a central organization with branches, and the Dorchester Labourers of 1834 discovered the peril into which the ritual of oaths might lead innocent men.

These deterrents were removed by enabling legislation. In 1829 a central authority, the Registrar of Friendly Societies, was appointed to supervise Friendly Societies, and between 1829 and 1875 further privileges and safeguards were conferred. But the Friendly Society Movement throughout the nineteenth century was wholly voluntary. In 1911 the situation was suddenly reversed by the passing of the National Insurance Act.

The Co-operative Societies were more suspect. They crept into legal recognition as the children of the Friendly Society, under the 'frugal investments' clause of the Act of 1846, being compelled by the legal prejudice against association in restraint of trade to adopt this unnatural mother. Their real nature was recognized in 1852, when they were brought under the Industrial and Provident Societies Act, and in 1862, when they were granted the boon of limited liability. But the accident of their legal origin still survives; for they are regulated to-day by the Industrial and Provident Societies Act of 1893. The Co-operative Movement is now drawing closer to politics, following the lead of most of the continental countries, notably Belgium and Germany. Though we cannot say that there is any indication of the State taking over the movement, we may note that the growth of municipal trading in the 'nineties was, in principle, an application of the consumers' association to monopolies of distribution such as tramways, water, electricity, and gas.

The State was altogether hostile to the growth of the Trade Union. The Charter of Emancipation, won by the guile of Francis Place in 1824, was severely curtailed in 1825. Huskisson[68] depicted in lurid terms the tyranny of a military trades unionism, 'representing a systematic union of the workers of many different trades'. It was a 'kind of federal republic', whose mischievous operations, if not checked, would keep the commercial classes 'in constant anxiety and fear about their interests and property'. Arnold, of Rugby, a decade later wrote of them in the same strain: 'you have heard, I doubt not, of the trades unions; a fearful engine of mischief, ready to riot or assassinate; and I see no counteracting power.'[69]

The counteracting power was their own weakness. The early militancy burnt itself out, and was succeeded at the turn of the century by a 'New Spirit and a New Model'. The new spirit was anti-militant, and the new model was a trade union representing the elite of the skilled trades. The Amalgamated Society of Engineers was founded in 1850 and served as a model to the Carpenters, Tailors, Compositors, Iron-founders, Brick-layers, and others. The Trades Unions were now respectable, and in 1867 the State recognized the fact.

The period of collectivism is denoted by the growth of the Labour Party in Parliament, and the increasing part played by the State in industrial disputes and the regulation of wages. The nationalization of railways and the nationalization of mines are burning questions.

4. In all the movements we have described, the spiritual stimulus, the initial drive, and the solid successes have been provided by voluntary association. The State has not been the pioneer of social reform. Such a notion is the mirage of politicians. It has merely registered the insistent demands of organized voluntary effort or given legal recognition to accomplished facts. This is the distinctive note of English social development in the nineteenth century.

FOR REFERENCE

Dicey, Law and Opinion.

Robinson, The Spirit of Association.

Hovell, The Chartist Movement.

Sombart (tr. Epstein), Socialism and the Socialist Movement.

[Cd. 9236], Report of Committee on Trusts.

FOOTNOTES:

[Footnote 20: From the writer's forthcoming book Life and Labour in the Nineteenth Century, to be published by the Cambridge University Press.]

[Footnote 21: Tooke and Newmarch, History of Prices, v. 356.]

[Footnote 22: Commons Committee on Emigration, 1827, Q. 1761.]

[Footnote 23: Commons Committee on the Condition of Labourers employed in the Construction of Railways, 1846, Q. 866.]

[Footnote 24: Ibid., Q. 217.]

[Footnote 25: Ibid., Q. 897.]

[Footnote 26: Ibid., Q. 733.]

[Footnote 27: Ibid., Q. 193.]

[Footnote 28: Ibid., Qs. 869-78.]

[Footnote 29: Report of Poor Law Commissioners on the Employment of Women and Children in Agriculture (1843), pp. 20, 25.]

[Footnote 30: Ibid., pp. 299-300.]

[Footnote 31: Report of Commissioners on the Employment of Young Persons in Agriculture, p. 64.]

[Footnote 32: Dr. Cook Taylor, Letter to the Morning Chronicle, dated from Rossendale Forest (Lancashire), June 20, 1842.]

[Footnote 33: Rural Rides, i. 219.]

[Footnote 34: Poor Law Commission of 1834, Appendix.]

[Footnote 35: Hand-loom Weavers' Commission, Final Report, 1841, p. 18.]

[Footnote 36: Hand-loom Weavers' Commission, Assistant-Commissioner's Report, 1840, Part IV, pp. 76-81.]

[Footnote 37: Second Annual Report of the Poor Law Commissioners, 1836.]

[Footnote 38: Hand-loom Weavers' Commission, Assistant-Commissioner's Report, Part III, p. 551.]

[Footnote 39: Anti-bread Tax Circular, No. 91, June 16, 1842.]

[Footnote 40: First Report of the Factory Commissioners, 1833, p. 27.]

[Footnote 41: Report of Commissioner on the Condition of the Framework Knitters (1845), p. 109.]

[Footnote 42: Ibid., p. 115.]

[Footnote 43: William Felkin, History of the Machine-wrought Hosiery and Lace Manufactures (1867), p. 458.]

[Footnote 44: Evidence before the Truck Commissioners (1871), Q. 37,500.]

[Footnote 45: Pamphlet of 1825, p. 14.]

[Footnote 46: Home Office Papers, 40, Letter from R.J. Blewitt, Esq., M.P., November 6, 1839.]

[Footnote 47: Richard Fynes, Miners of Northumberland and Durham, p. 72.]

[Footnote 48: John Wilson, History of the Durham Miners' Association (1870-1904), p. 40.]

[Footnote 49: Report of Commissioner on the State of the Mining Population (1846).]

[Footnote 50: These pamphlets are in the British Museum.]

[Footnote 51: Report of Commissioner on the State of the Mining Population (1850).]

[Footnote 52: Ibid. (1852).]

[Footnote 53: Royal Commission, First Report (Mines), p. 27.]

[Footnote 54: Ibid., p. 21.]

[Footnote 55: Royal Commission, Second Report (Trades and Manufactures), p. 147.]

[Footnote 56: Ibid., pp. 155-6.]

[Footnote 57: Midland Mining Commission, First Report, p. 34.]

[Footnote 58: Ibid., p. 91.]

[Footnote 59: Ibid., p. 44.]

[Footnote 60: Rural Rides, ii. 353.]

[Footnote 61: Commons Committee, Stoppage of Wages (Hosiery, 1854). Evidence of Mr. Tremenheere.]

[Footnote 62: Evidence before the Truck Commissioners, Q. 33,670.]

[Footnote 63: Truck Commission, 1871. Report, p. 16.]

[Footnote 64: Commons Committee, Stoppage of Wages in the Hosiery Manufacture (1854), Q. 80.]

[Footnote 65: Commons Committee of 1816, pp. 64 and 73.]

[Footnote 66: Ibid., p. 38.]

[Footnote 67: Ibid., p. 28.]

[Footnote 68: Speech, March 29, 1825.]

[Footnote 69: Letter to the Chevalier Bunsen, 1834, quoted in Strachey, Eminent Victorians, p. 197.]



VIII

ATOMIC THEORIES

PROFESSOR W.H. BRAGG, C.B.E., D.SC., F.R.S.

When a lecture on the progress of Science is given before a conference concerned largely with historical subjects, it is not inappropriate to point out that Science has a history of its own and that its progress makes a connected story. The discovery of new facts is not made in an isolated fashion, nor is it a matter of pure chance, unaffected by what has gone before. On the contrary, scientific progress is made step by step, each new point that is reached forming a basis for further advances. Even the direction of discovery is not entirely in the explorer's control; there is always a next step to be taken and a limited number of possible steps forward from which a choice can be made. The scientific discoverer has to go in the direction in which his discoveries lead him. When discoveries have been made it is possible to think of uses to which they may be put, but in the first instance all discoveries are made without any knowledge whatever of what use may afterwards be made of them.

Consequently scientific progress is a quite orderly advance, not a spasmodic collection of facts, and in the truest sense of the word it has a history. In order that opportunities for this steady progress may be provided it is very important that this point should be fully appreciated. Every one, for example, is vaguely conscious that science played a great part in the War. As a consequence the number of students of science has greatly increased; manufacturing firms are awakening to the fact that they must pay more attention to scientific development and are founding research laboratories. It is very important that this awakened attention should be well informed, and for that reason it cannot be pointed out too often that the scientific work which has been the basis of all material progress can only be turned to definite material ends in the last stages of its development. Fundamentally everything rests on the pure attempt to gain knowledge without any idea of the use to which it may subsequently be put. Without pure science there is no applied science at all. It is quite right in my opinion that the researcher in pure science should have with him the hope that what he does may one day be of direct benefit to others. But it is probable that he does not in his own mind confine the idea of possible uses to such material matters as I have mentioned above and as are so prominent at present. He believes that his work has a less material side whose value need not be explained to the present audience.

In the general line of progress it is natural to find that there are certain broad roads along which the main advance has been directed. Students of physics and chemistry and the subjects which are allied to them find that they are in general considering either matter, or electricity, or energy. I make this classification, not from any philosophical point of view, but simply for present convenience. The first important principle to which I would like to draw your attention is that each of these things can be measured quantitatively. If we accept the weight of a substance as an indirect measure of the amount of matter present, then we all know we can express the amount of matter in any given body in terms of a fundamental unit, like a pound or a gramme; and the idea has been put to immemorial use. In later years we have learnt that electricity itself is also a quantity and that the amount of electricity which stands on an electrified body, or flows past a given point in an electric conductor, as for example the wire connected to an electric light, can be expressed arithmetically in terms of some unit. Instruments are made for the purpose of measuring quantities of electricity in terms of the legal standard. It is one of the functions of a Government Institution, like the National Physical Laboratory, to test such instruments and report on their accuracy. International conferences have been held for the purpose of reducing these units to as small a number as possible so that people may be able to trade less wastefully and more conveniently, so that also the barriers between peoples may be broken down and the interchange of ideas as well as of materials may be made more easily. Without an arrangement of this kind it would be impossible to carry on industrial life in which use is made of electricity. It would be as difficult as to hold a market without the use of weights and scales, more difficult, in fact, since anyone can estimate the size of a piece of cloth or the amount of corn in a sack, but no one has a natural sense by which he can estimate an amount of electricity.

In just the same way energy can be measured as a quantity in terms of a fundamental unit. The discovery that this was so was made by Joule and others towards the middle of the nineteenth century, and lit the road for further advance as a dark street is lit by the sudden turning-up of the lamps. All modern industry rests on this principle. We are now so accustomed to the idea that energy is a quantity that we can hardly realize a time when it was merely a vague term. If we want an illustration of how thoroughly we have grasped this idea let us remember that when we pay our electric-light bill we pay so much money for so many units of energy supplied; for so much energy, let us note, not for so much electricity, since we take into account not only the actual amount of electricity driven through our house wires, but also the magnitude of the force which is there to drive it. Energy exists in many forms: energy of motion, heat, gravitational energy, chemical energy, radiation, and so on. In the transformations of energy which are continually occurring in all natural processes, there is never any change in the total amount of energy. This is the famous principle of the Conservation of Energy. Sometimes it is stated in the form 'Perpetual motion is impossible'.

One of the most important forms of energy is radiation. The constant outpouring by the sun of energy in this form is vital to us. The fact was obvious long ago and that is one of the reasons why light and heat have interested students of science in all ages.

There exist then three main subjects of study—matter, electricity, and energy. These themselves and their mutual relations have been, and are, the principal objects of interest to the scientific student, and from our strivings to understand them we have learnt most of what we know. All three are quantities and all are expressible in terms of units.

Now there is one point which I have thought would especially interest you. A very remarkable tendency of modern discovery shows more and more clearly that not only are these things quantities which we can express in units of our own choosing, but that Nature herself has already chosen units for them. The natural unit does not, of course, bear any exact connexion with our own. This being so, it must be of the utmost importance that we should know what these natural units are and so be able to understand what Nature is ready to tell us. Nature has chosen to speak in a certain language; we must get to know that language.

In the first place we know surely that there are natural units of matter. This was the great discovery made by Dalton in the beginning of the nineteenth century. When he found that each of the known elements, such as copper or oxygen or carbon, consisted ultimately of atoms, all the atoms of any one element being alike, he laid the foundation on which the huge structure of modern chemistry has been raised. The chemist takes one or more atoms of one element, one or more of another, and may be of a third or fourth, and he puts them together into a compound which we call a molecule. The molecule for example of ordinary salt contains always one atom of chlorine and one of sodium. Chlorine and sodium are elements, salt is a compound. Six atoms of carbon and six of hydrogen put together in a certain way make benzene. In the same way every substance that we meet is capable of analysis, showing ultimately the molecules as made up, according to a definite plan, of so many atoms of the various elements. In analytical chemistry molecules are dissected in order to discover the mode of their building; in synthetic chemistry the atoms are put together to make a molecule which is already known to have, or even may be anticipated to have, certain properties. This is the work of the chemist. Sometimes enormous forces are concerned in this pulling apart and putting together, witness the terrific power of modern explosives. But the same kind of handling by the chemist may be devoted to the delicate construction of a molecule which gives a certain colour to the dyer's vat and so pleases the eye that the great cloth industries feel the consequence, and nations themselves are affected by the flow of trade. After all, since the processes of the physical world operate ultimately through the power and properties of molecules, it is not surprising that the chemist's work in these and numberless other ways has such tremendous influence in the world.

Here then by the recognition of the units of matter which Nature has chosen for herself it has been possible to do great things.

It should be observed that the atom, in spite of its name, is not something which is incapable of all further division; it is only incapable of retaining its properties on division. When an atom of radium breaks down in the unique operation during which its singular properties are manifested, it dies as radium and becomes two atoms, one of helium, the other of a different and rare substance. It will interest you to know that the airships of the future are expected to be filled with this non-inflammable helium.

The discovery of the atomic nature of electricity came later. Faraday established the fact that in certain processes there was more than a hint that electricity was always present in multiples of a definite unit. In the process called electrolysis the electric current is driven across a cell full of liquid containing molecules of some substance. When the electricity passes there is a loosening of the bonds that bind together the atoms of the molecule, and a separation; atoms of one kind travel with the electricity across the cell and are deposited where the current leaves the cell; the other kind travel the opposite way. In this way for example we deposit silver on metal objects in electro-plating processes, or separate out the purest copper for certain electrical purposes. The striking thing which Faraday discovered was that the number of atoms deposited always bore a very simple relation to the quantity of electricity that passes. The same current passing in succession through cells containing different kinds of molecules broke up the same number of molecules in each cell. It was as if in each electrolytic cell atoms of matter and atoms of electricity travelled together. The movement of an atom meant the simultaneous movement of a definite quantity of electricity. Electricity was, so to speak, done up in little equal parcels, and an atom of matter on the move, which was termed an ion, or wanderer, carried, not a vaguely defined amount of electricity, but one of these definite parcels.

It was not, however, until the later years of the nineteenth century that the natural unit of electricity was manifested by itself and without a carrier. At a famous address to the British Association at York in 1881 Sir William Crookes described the first marvellous experiments in which this feat had been accomplished, though there was still to come a long controversy before the interpretation was clearly accepted. It is now definitely established that there is a fundamental atom of electricity which we now call the electron. As we all know electrification is of two kinds—a positive and a negative. The electron is of the negative kind. There does not appear to be a corresponding positive atom of electricity, or at least not one that is so singular in its properties as the electron. Electrons go to the making of all atoms, just as atoms go to the making of molecules. The atom which is neutral, that is, shows neither positive nor negative electrification, must contain positive electricity in some form to balance the electrons which we know it contains. When we strip an atom, as we know how to do, of one or more of these electrons, the remainder is positively charged. The positive ion is any sort of an atom or molecule which has become positively electrified in this way. An atom which has become positive by the loss of one or more of its electrons exercises a force on any spare electrons in its neighbourhood or on any atom carrying a spare electron. When there are large numbers of atoms seeking in this way to become neutral once more, as occurs often in Nature, the forces generated may be tremendous. They are shown, for example, in the lightning-stroke. But indeed it would seem that all the chemical forces of which we have already spoken depend ultimately upon the electric state of the atom concerned.

It is because the force which a positively-charged atom exerts on an electron is so great and because the electron is so light and easily moved compared to an atom that the electron has not been isolated at will until recent years. The isolation in fact depends upon the electron being endowed with a sufficient speed to carry it through or past the action of an atom which is seeking to absorb it into its system. A lump of matter flying in space might enter our solar system with such speed as to be able to pass through and go on its way almost undeflected. Or again, it might have a much lower speed and go so much nearer the sun that it was seriously deflected in its course, as we see in the case of comet visitors. But if for some reason or other the lump of matter found itself inside the solar system without the endowment of high velocity it would certainly be absorbed. Just so an electron can pass through an atom with or without serious deviation from its line of motion, provided that motion is rapid enough. Only recently have we been able to exert electric forces of sufficient strength to set an electron in motion with the speed it must have if it is to maintain an individual existence Now we can gather electrons at will, dragging them from the interior of solid bodies, and hurl them with tremendous speed like a stream of projectiles. Since in the open air the speed is soon lost by innumerable collisions with the air-molecules, the effect can only be studied satisfactorily in a glass bulb from which the air has been evacuated. Crookes made great improvements in air-pumps during an investigation on thallium, and consequently was able to obtain the high vacuum required for the experiment with the electron streams. It was afterwards found by Roentgen that when an electron stream in an evacuated bulb was directed upon a target placed within the bulb, a remarkable radiation issued from the target. Thus arose the so-called X or Roentgen rays. As you all know they have for many years played a most important part in surgery and medicine. You may have heard that during the war they were also used to examine the interior of aeroplane constructions and to look for flaws invisible from without. Although X-Rays are of the same nature as light rays they can penetrate where light rays cannot, passing in greater or less degree through materials which are opaque to visible light and allowing us to examine the interior which is hidden from the eye.

Every electric discharge is essentially a hurried rush of electrons. When we rub two bodies together and they become electrified we have in some way or other torn electrons from one of the bodies and piled them on the other. The former becomes the positively charged body and the latter the negative. A film of moisture stops this action. When wool is spun in factories it tends to become in certain stages of the process too dry and too free from grease; the yarn then becomes electrified as it passes over the leather rollers, and when the machine tries to spin the threads together they fly apart and refuse to join up the minute hooks with which the wool fibres are furnished. The spinning operation would come to an end were there not means provided by which the air can be so filled with moisture that the fibres become damp and the action ceases. So in some cases a stream of air filled with positive and negative ions is made to play upon the fibres; the fibres select what ions they want, and so neutralizing themselves, spinning can proceed again.

When a current of electricity runs along a wire there is in fact nothing more than a procession of electrons. The stream of electrons that runs through the filaments in the lamps that light this room, raising the filaments to a white heat, are set in motion by the dynamos in the city. There is a complete wire circuit, including the dynamo, the conductors, and the lamps. When the dynamos are not working the electrons do not as a whole move either way, though they are always there. When the dynamo begins to turn, the electrons set out on their continuous journey.

Electrons are involved in the emission of wireless signals, and in their receipt. The so-called 'valve', which multiplies minute electric signals and was so greatly improved during the war, depends entirely on the action of electrons, and the brilliant experimental work was based on the newly-acquired knowledge of their properties.

I have told you that under certain circumstances a stream of electrons may generate X-Rays, in reality a form of light rays. This action is a very common one, and it is curious that the faster the electron goes the shorter is the wave-length of the radiation. A very fast electron generates an X-Ray of so short a wave-length that the penetrating power of the ray, which goes with the shortness of the wave, is excessive, and in this way we may have rays which go right through the human body or even through inches of steel. As the speed of the exciting electron becomes less, the X-Rays are less penetrating. With still slower electrons we may generate ordinary light, and it will take a slower electron to generate red than to generate blue. The slowest electrons we use in this way have a speed of many hundred miles per second; the fastest have a speed which nearly approaches that of light, or 186,000 miles a second.

And conversely radiation can set electrons in motion. When X-Rays are driven into a patient's body electrons are set in motion within, and moving over certain minute distances, initiate chemical actions which are necessary to some cure. Or they may go right through the body and fall on a photographic plate, setting in operation chemical action which forms a picture on the plate.

There is another occasion of an entirely different kind when the electron is greatly in evidence and displays effects which are most astonishing and significant. Every atom of radium or other radio-active substances sooner or later meets with the catastrophe in which its life as radium ends and atoms of other substances are formed. At that moment occurs the emission which is the characteristic property of the substance. One of the radiations emitted consists of high-velocity electrons, moving, some of them, nearly as fast as light.

Now it is found that when the speed approaches that of light, 186,000 miles or 3 x 10^{10} centimetres per second, the energy is higher than it should be if it followed the usual rule, viz. energy is equal to half the mass multiplied by the square of the velocity. It would seem that an electron moving with the velocity of light would have infinite energy; or, to put the matter in another way, the experimenter in his laboratory can never hope to observe an electron moving so fast; it would be the end of his laboratory and of himself if ever it turned up.

Linked up with this result is the very strange fact that no one has ever been able to find any direct evidence of the existence of the ether, which is postulated in order to carry light-waves. It has been pictured as a medium through which the heavenly bodies move, and to which their motions may be referred. But when light is launched into the ether, its apparent velocity must depend on whether it travels with or against the drift of the ether through the laboratory where the measurement is made. The experiment has been performed without the discovery of any such difference, although the method was amply accurate enough to detect the effect that might be expected. It was afterwards shown that the negative result might be explained by supposing that a measure of length varied in length according to whether it was travelling with or against the ether. But the continual failure of all such experiments has led to a remarkable hypothetical development with which the name of Einstein is firmly connected. It is supposed that some flaw must exist in our fundamental hypotheses, and that if this were corrected we should then find that we ought to get the same value for the velocity of light however and whenever we measured it, and at the same time we should find that no measurement of the velocity of a body moving relative to the observer would ever equal the velocity of light. The hypothesis denies the existence of an absolute standard to which motions can be referred, and insists that they must all be considered relatively to the observer. It is called the principle of relativity. Calculations of its consequences begin with the necessary changes in the fundamentals, such as Einstein has introduced.[70]

Time does not allow me to say more of the innumerable ways in which electrons play an essential part in all the processes in the world. We have long believed that this is so, but the picture has never been so clear to us as it is now; and with our understanding our power is increased. Yet once more the illumination of our understanding comes from our recognition that Nature has preferred the discrete to the continuous and that electricity is not infinitely divisible but is, like matter, and even more simply than matter, of an atomic structure. And we have found the unit and learnt how to handle it.

It is even more strange that it may now be said of energy that there are signs of atomicity. It may seem absurd to think that the energy which is transformed in any operation is transformed in multiples of a universal unit or units, so that the operation cannot be arrested at any desired stage but only at definite intervals. Indeed we have no right to assert that this is always true. But undoubtedly there are cases in which the atomicity of energy is clear enough, as for example in the interchange of energy between electrons in motion and radiation. It is remarkable that when radiation sets an electron in motion, the electron acquires a perfectly definite speed depending only on the wave-length of the radiation and not on its intensity, and has apparently absorbed from the radiation a definite unit of energy. Radiation of a particular wave-length cannot spend its energy in this way except in multiples of a certain unit, because each of the electrons which it sets in motion has the same initial energy, which it must have got from the radiation. In other words, energy of radiation of the particular wave-length can only be transformed into energy of movement of electrons in multiples of a certain 'quantum' peculiar to that wave-length. The intensity of the radiation, that is to say, the amount of energy moving along the beam, can only affect the number of electrons set in motion and not the speed of any one of them. During the last few years a very extraordinary theory has been developed on the basis of these and similar facts. I doubt if it would be more profitable to give further instances at present, but I have mentioned it because it seems to show looming on the horizon of our knowledge another tendency of Nature to make use of the atomic principle.

I will only add that the whole position of physics is indeed at this time of extraordinary interest, and at any moment there may be some great discovery or illuminating thought which will explain the present startling difficulties and open up new worlds of thought.

FOR REFERENCE

Bragg, Rays and Crystals (Ball & Sons).

FOOTNOTES:

[Footnote 70: Since this address was given, the results of the Eclipse Expedition to Brazil are considered to have confirmed in a satisfactory manner one of the most remarkable deductions made by Einstein from the principles which he maintains. The matter has roused so much interest that some of the leading exponents of the relativity principle have published careful accounts intended for students not familiar with it: it would therefore be superfluous to discuss the matter here.]



IX

PROGRESS IN BIOLOGY DURING THE LAST SIXTY YEARS

PROFESSOR LEONARD DONCASTER, F.R.S.

On November 24, 1859, The Origin of Species was published, and this date marks the beginning of an epoch in every branch of biology. Before it, Biology had been almost entirely a descriptive science, but within a few years after the publication of the Origin its effects began to colour all aspects of biological research. A co-ordinating and unifying principle had been found, and the leading idea of biologists ceased to be to describe living things as they are, and became transformed into the attempt to discover how they are related to one another. The first effect of this change of attitude was chiefly to turn biologists towards the task of tracing phylogenetic or evolutionary relationships between different groups of animals—the drawing up of probable or possible genealogical trees and the explanation of natural classification on an evolutionary basis. When once, however, the notion of cause and effect, or more correctly of relationship, between the phenomena seen in living beings had become familiar to biologists, it spread far beyond the limits of tracing genealogical connexions between different animals and plants. It made possible the conception of a true Science of Life, in which every phenomenon seen in a living organism should fall into its true place in relation to the rest, and in which also the phenomena of life should be correlated with those discovered in the inorganic sciences of Chemistry and Physics.

The history of the various branches of biological science in the past sixty years reflects the general course of these tendencies. Until shortly after 1859, the study of morphology, or the comparative structure of animals (and of plants) was intimately related with that of physiology, that is, with the study of function. In the years following the appearance of the Origin, however, anatomists and morphologists were seized with a new interest. For the time at least, the chief aim in studying structure was no longer to explain function, but rather to explain how that structure had come into being in the course of evolution, and how it was related with homologous but different structures in other forms. The result was a tendency to a divorce between morphology and physiology, or at least between morphologists and physiologists, which led to the division into two more or less distinct sciences of what had hitherto been regarded as closely inter-related branches of one. The greater men of the early part of the period, such as Huxley, remained both morphologists and physiologists, but most of their followers fell inevitably into one or the other group, and in discussing the later phases of biological progress it will be necessary to keep them separate.

Apart from its effect on the systematic and anatomical side of Biology, the idea of Evolution, and especially of Darwin's theory of Natural Selection, had important consequences on that side of the science which may be described as Natural History. Before the appearance of Darwin's work, Natural History consisted chiefly in the observation and collection of facts about the habits and life-history of animals and plants, which as a rule had no unifying principle unless they were used, as in the Bridgewater Treatises, to illustrate 'the power, wisdom, and goodness of God'. Now, however, a new motive was provided—that of discovering the uses to the organism of its various colours, structures, and habits, and the application of the principle of natural selection to show how these characters conduced to the preservation and further evolution of the species. And out of this interest in the theory of natural selection grew in the last twenty years of the nineteenth century the greatly increased attention to the facts and theories of heredity, which was stimulated by Darwin's hypothesis of Pangenesis and especially by Weismann's speculations about the nature and behaviour of the 'germ-plasm'. Before the appearance of Weismann's work, the germ-cells, which bear somehow or other the hereditary characters that appear in the offspring, were supposed to be produced directly from the body of the parent. Darwin provisionally suggested that every cell of every organism gives off minute particles which become congregated in the germ-cells, and that these cells thus contain representative portions of all parts of the parent's body. Weismann, on the basis of his work on the origin of the germ-cells in Medusae and Insects, maintained that these cells are not derived from the body, but only from pre-existing germ-cells stored within it—that, in fact, although an egg gives rise to a hen, a hen does not give rise to an egg, but only keeps inside her a store of embryonic eggs which mature and are laid as the time comes round. The theory had to be modified to suit the facts of regeneration and vegetative reproduction, but in essence it was accepted by the biological world and is the orthodox opinion (if such a word may be used in Science) at the present day. The difference between the two views is not only of theoretical interest, for it involves the whole question of whether characteristics acquired by an individual during its life in response to external conditions can or cannot be transmitted to offspring. If the germ-cells contain representatives of all parts of the body, modifications impressed on the body during its life may at least possibly be transmitted to offspring born after the modifications have taken place. If, however, the germ-cells are independent of the rest of the body, and only stored within it for safe-keeping like a deed-box in the vaults of a bank, it would seem impossible for any environmental influence, whether for good or ill, to take effect on the offspring. This controversy on the heritability of 'acquired characters' was one of the most important towards the end of last century, and although the majority of biologists now follow Weismann in so far as they deny that 'acquired' characters are transmissible, the question is not yet completely settled; all that can be said is that, in spite of many attempts to prove the contrary, there is no satisfactory evidence of the transmission to offspring of effects impressed on the body of the parent, unless the germ-cells themselves have been affected by the same cause—as for example in some cases of long-continued poisoning by alcohol or similar drugs.

While the problem of the transmission of acquired characters, and of the cause of variation and its relation to evolution, was occupying much of the attention of biologists, the whole problem entered upon a new phase in the year 1900 with the re-discovery of Mendel's work on heredity. Mendel worked with plants, and published his results in 1865, but at that time the biological world was too much occupied with the fierce controversy which raged over The Origin of Species to take much notice of a paper the bearing of which upon it was not appreciated. Mendel's discovery never came to the notice of Darwin, was buried in an obscure periodical, and remained unknown until many years after the death of its author. In 1900 it was unearthed, and, largely owing to the work of Bateson, it rapidly became known as one of the most important contributions to Biology made during the period under review.

This is not the place to describe in detail the nature of Mendel's theory. Its essence is, firstly, that the various characteristics of an organism are in general inherited quite independently of one another; and, secondly, that the germ-cells of a hybrid are pure in respect of any one character, that is to say, that any one germ-cell can only transmit any unit character as it was received from one parent or the other, and not a combination of the two. This leads to a conception of the organism as something like a mosaic, in which each piece of the pattern is transmitted in inheritance independently of the rest, and in which any piece cannot be modified by association with a different but corresponding piece derived from another ancestor. It is impossible to say as yet whether this conception at all completely represents the nature of the living organism, but it is one which is exercising considerable influence in biological thought, and if established it will mark a revolution in Biology hardly inferior to that brought about in Physics and Chemistry by the discovery of radio-activity.

An important consequence of the advance in our knowledge of heredity associated with the work of Mendel and his successors is a tendency to doubt whether natural selection is of such fundamental importance in shaping the course of evolution as was supposed in the years of the first enthusiasm which followed the publication of the Origin.

Darwin based his theory of Natural Selection on the belief which he derived from breeders of plants and animals, that the kind of variation used by them to produce new breeds was the small and apparently unimportant differences which distinguish a 'fine' from a 'poor' specimen. He supposed that the skilled breeder picked out as parents of his stock those individuals which were slightly superior in one feature or another, and that by the accumulative effect of these successive selections not only was the breed steadily improved, but also, by divergent selection, new breeds were produced. Experience shows, however, that although this method is used to keep breeds up to the required standard, it is rarely, if ever, the means by which new breeds arise. New breeds commonly come into existence either by a 'sport' or mutation, or by crossing two already distinct races, and by selecting from among the heterogeneous descendants of the cross those individuals which show the required combination of characters. And it is further found that most of the distinguishing features of various breeds of domestic animals and plants are inherited according to Mendel's Law, suggesting that each of these characters is a unit, like one piece of a mosaic, independent of the rest. Now it is easy to see how the selection of small, continuously varying characters could take place in Nature by the destruction of all those individuals which failed to reach a certain standard, but it is much more difficult to understand how natural selection could act on comparatively large, sporadic, unco-ordinated 'sports'. There is thus a distinct tendency at present to regard natural selection as less omnipotent in directing the course of evolution than was formerly supposed, but it must be admitted that no very satisfactory alternative hypothesis has been suggested. Some have supposed that there is a kind of organic momentum which causes evolution to continue in those directions in which it has already proceeded, while others have postulated, like Bergson, an elan vital as a kind of directive agency. Others again have reverted towards the older belief in the inherited effects of environment—a belief which, in spite of the arguments of Weismann and his followers, has never been without its supporters. The present condition of this part of biology, as of many others, is one of open-mindedness approaching agnosticism. There is dissatisfaction with the beliefs which satisfied the preceding generation, and which were held up almost as dogmas, but there is no clear vision of the direction in which a truer view may be sought.

Before leaving this side of the subject, reference must be made to one important aspect of modern work on heredity—that of the inheritance of 'mental and moral' characteristics. As a result of the work of the biometric school founded by Galton and Pearson, it has been shown that the so-called mental and moral characteristics of man are inherited in the same manner and to the same extent as his physical features. Of the theoretical importance of this demonstration this is not the place to speak; its practical value is unquestionable, and may in the future have important effects on sociological problems.

Another notable line of advance, entirely belonging to the period under review, and chiefly the product of the present century, is seen in the science of Cytology—the investigation of the microscopic structure of the cells of which the body is composed. The marvellous phenomena of cell and nuclear division have revealed much of the formerly unsuspected complexity of living things, while the universality of the processes shows how fundamentally alike is life in all its forms. In recent years great progress has been made in correlating the phenomena of heredity and of the determination of sex with the visible structural features of the germ-cells. Weismann attempted a beginning of this over thirty years ago, but the detailed knowledge of the facts was then insufficient. Since the discovery of Mendel's Law, a great amount of work has been done, chiefly in America, by E.B. Wilson and T.H. Morgan and their pupils, on tracing the actual physical basis of hereditary transmission. Although the matter is far from being completely known, the results obtained make it almost indubitable that inherited characters are in some way borne by the chromosomes in the nuclei of the germ-cells. The work of Morgan and his school has shown that the actual order in which these inherited 'factors' are arranged in the chromosomes can almost certainly be demonstrated, and his results go far to support the conception of the organism, referred to above, as a combination or mosaic of independently inherited features.

It was said at the beginning of this sketch that most of the more notable lines of advance in Biology could be traced back to the impetus given by the acceptance of the theory of Evolution, and the desire to test and prove that theory in every biological field. It is most convenient, therefore, to take this root-idea as a starting-point, and to see how the various branches of study have diverged from it and have themselves branched out in various ways, and how these branches have often again become intertwined and united in the later development of the science.

Perhaps the most obvious method of testing the theory of evolution is by the study of fossil forms, and our knowledge of these has progressed enormously during the period under review. Not only have a number of new and strange types of ancient life come to light, but in some cases, e.g. in that of the horse and elephant, a very complete series of evolutionary stages has been discovered. In this branch, however, as in almost all others, the results have not exactly fulfilled the expectations of the early enthusiasts. On the one hand, evolution has been shown to be a much more complex thing than at first seemed probable; and on the other, many of the gaps which it was most hoped to fill still remain. A number of most remarkable 'missing links' have been discovered, such as, for example, Archaeopteryx, the stepping-stone between the Reptiles and the Birds, and the faith of the palaeontologist in the truth of evolution is everywhere confirmed. But the hope of finding all the stages, especially in the ancestry of Man, has not been realized, and it has been found that what at one time were regarded as direct ancestors are collaterals, and that the problem of human evolution is much less simple than was once supposed.

A second important piece of evidence in favour of evolution is provided by the study of the geographical distribution of animals, on which much work was done in the earlier part of the period under review. And in this connexion mention must be made of the science of Oceanography, for our whole knowledge of life in the abysses of the ocean, and almost all that we know of the conditions of life in the sea in general, has been gained in the last fifty years.

Another of the chief lines of evidence for the truth of the evolution theory is based on the study of embryology, and this also was followed with great vigour by the zoologists of the last thirty years of the nineteenth century. It is found that in many instances animals recapitulate in their early development the stages through which their ancestors passed in the course of evolution. Land Vertebrates, including man, have in their early embryonic life gill-clefts, heart and circulation, and in some respects skeleton and other organs of the type found in fishes, and this can only be explained on the assumption that they are descended from aquatic fish-like ancestors. On the basis of such facts as these, the theory was formulated that every animal recapitulates in ontogeny (development) the stages passed through in its phylogeny (evolution), and great hopes were founded upon this principle of discovering the systematic position and evolutionary history of isolated and aberrant forms. In many cases the search has led to brilliant results, but, as in the case of palaeontology, in many others the light that was hoped for has not been forthcoming. For it soon became evident that the majority of animals show adaptation to their environment not only in their adult stages but also in their larval or embryonic period, and these adaptations have led to modifications of the course of development which are often so great as to mask, or obscure altogether, the ancestral structure which may once have existed. Although, therefore, the results of embryological research have provided most convincing proof of the truth of the theory of evolution in general, they have not completely justified the hopes of the early embryologists that by this method all the outstanding phylogenetic problems might be solved.

The detailed study of embryology, however, has led to most important results apart from the particular purpose for which most of the earlier investigations in this field were originally undertaken. For the study of embryology, at first purely descriptive and comparative, was soon found to involve fundamental problems concerning the factors which control development. An egg consists of a single cell, and it develops by the division of this cell into two, then into four, eight, and so forth, until a mass of cells is produced. In some cases all these cells are to all appearance alike, or nearly alike; in others the included yolk is from the first segregated more or less completely into some cells, leaving the other cells without it. But in any case, after this process of cell-division has proceeded for a certain time, differentiation begins to set in—some cells become modified in one way, others in another, and from what was a relatively homogeneous mass an organized embryo, with highly differentiated parts, appears. The problem immediately propounds itself—what are the factors which control this differentiation? This problem is essentially a physiological one, and yet, since it arises most conspicuously in a field which has been worked by professed zoologists rather than physiologists, it has been studied more by those trained in zoology and botany than by those who have specialized in physiology. In this way, as in many other directions, such as in the study of heredity, of sex, and of the effects of the environment on the colours and structure of animals, the trend of zoology in recent years has returned towards the physiological side, and the old division which separated the sciences (but which has never so seriously affected students of plant life) is being obliterated.

Hence we are led back to consider the progress of Physiology as a whole—a subject with which the present writer hesitates to deal except in a very superficial manner. Physiology as an organized science has inevitably been deeply influenced by its close relation with medicine, with the result that through a large portion of the period under review it has concerned itself chiefly with the functions of the human body in particular, or at least chiefly with Vertebrates from which, by analogy, the human functions may be inferred. In this field it has made enormous progress, and a vast amount of knowledge has been gained with regard to the function and mechanism of all the parts and organs of the body. It may perhaps be suggested, however, that in the pursuit of this detailed (and in practice absolutely necessary) knowledge, physiologists have to some extent lost sight of the wood in their preoccupation with the trees. That is to say, while they have advanced an immense distance in their knowledge of organs, they have not yet got as far as might be hoped in the understanding of the organism—which is to say no more than that the great and fundamental problem of Biology, the nature and meaning of Life, is apparently almost as far from solution as ever. To this further reference will be made below.

The progress of Physiology has been so great in all its branches that it is difficult to decide which most deserve mention; perhaps the most important advances are those connected with the nervous system and with internal secretions. Little or nothing was known fifty years ago of the minute structure of the nervous system, nor of the special functions of its different parts. Now the main functions of the various parts of the brain, and the relation of these parts to the activities of the other organs of the body, are well known, although much remains to be discovered with regard to the more detailed localization of function. The study of the microscopic structure of brain and nerve, and experiment on the conduction of nervous impulse, have given us some insight into the mechanism of the nervous system, but the fundamental nature of nervous action still remains unsolved.

The nervous system is the chief co-ordinating link between the various organs of the body, but in recent years it has been discovered that the relations of the different parts to one another are greatly influenced by substances known as internal secretions or 'hormones'. These substances are produced by ductless glands (the thyroid, suprarenals, &c.), from which they diffuse into the blood-stream and exercise a remarkable influence either on particular organs or systems, or on the body as a whole. Some of these secretions act specifically on the involuntary muscles of the body, others control growth, others the development of the secondary sexual characters, such as the distinctive plumage of male birds, and also greatly influence the sexual instinct. Much still remains to be discovered with regard to them, but it seems clear that they are of immense importance in the economy of the body. It has been suggested, without much experimental support, however, that if a part of the body becomes modified by use or environment, it may produce a modified hormone, and that so, by the action of this on the germ-cells, the modification may be transmitted to subsequent generations.

Before leaving the subject of physiology in the more special or technical application of the term, reference must be made to another science the growth of which has been largely under the influence of medicine. This is bacteriology, one of the newest branches of biology, and yet one which both from its practical importance and from the theoretical interest of its discoveries is rapidly taking a foremost place. Of its practical achievements in connexion with disease, and with the part played by bacteria and other minute organisms in the life and affairs of man, it is not necessary to speak. Every one knows the great advances that have been made in recent years in identifying (and to a less extent in controlling) disease-producing organisms, whether bacteria, protozoa (such as the organisms causing malaria, dysentery, etc.), or more highly organized parasites. The attempt, however, to combat these pathogenic bacteria has led to discoveries of the highest importance with regard to the production of immunity, not only against specific germs, but against many organic poisons such as snake venom and various vegetable toxins. That an attack of certain diseases leaves the patient immune to that disease for a longer or shorter time has of course been known for centuries, but it is a modern discovery that a specific poison induces the body to produce a specific antidote which neutralizes it, and the detailed working out of this principle and the study of the means by which the immunity is brought about promise to lead us a long way towards the central problem of the nature and activities of life itself.

We have seen how zoology has been led back into physiological channels of research, and how the study of bacteria is opening up some of the deepest problems of the reaction of living things to environmental stimuli, and just as the various branches of these sciences interlace and influence one another, so all of them, in recent years, have been coming into contact with the inorganic sciences of chemistry and physics. One of the noteworthy features of science in all its branches in recent years has been the tendency of subjects which were at one time regarded as distinct to come together again and to find that the problems of each can only be successfully attacked by the co-operation of the others. In their earlier days the biological sciences were in most respects far removed from chemistry and physics; it was recognized, of course, that organisms were in one sense at least physico-chemical mechanisms, consisting of chemical elements and subject to the fundamental laws of matter and energy. With the advent of the theory of evolution this conception of the organism as a mechanism took more definite shape, and among many biologists the belief was held that in no very long time all the phenomena of life would be explicable by known physico-chemical laws. Hence arose the scientific materialism which was so widespread in the years following the general acceptance of Darwin's theory. It was recognized, of course, that our knowledge of organic chemistry was at the time entirely inadequate to place this belief upon a proved scientific basis, but the expectation of proving it gave a great impetus to the study of the physical and chemical phenomena of life. This attempt was still further stimulated by the investigation of the factors controlling development referred to in a preceding paragraph, for it is evident that to a great extent at least these factors are chemical and physical in nature. And concurrently, the great advances in organic chemistry, resulting in the analysis and in many cases in the artificial synthesis of substances previously regarded as capable of production only in the tissues of living organisms, made possible a much more thorough investigation of the chemical and physical basis of vital phenomena. The result of this has been that to a quite considerable extent the factors, hitherto mysterious, which control the fertilization, division, and differentiation of the egg, the digestion and absorption of food, the conduction of nervous impulses, and many of the changes undergone in the normal or pathological functioning of the organs and tissues, can be ascribed to chemical and physical causes which are well known in the inorganic world.

As in other instances, however, some of which have been mentioned above, the elucidation of the organism from this point of view has turned out to be a much less simple process than the more sanguine of the early investigators supposed. The more knowledge has progressed, the more complex and intricate has even the simplest organism shown itself to be, and although the mechanism of the parts is gradually becoming understood, the fundamental mystery of life remains as elusive as ever.

The chief reason for this failure to penetrate appreciably nearer to the central mystery of life appears to be the fact that an organism is something more than the sum of its various parts and functions. In tracing the behaviour of any one part or function, whether it be the conduction of a nervous impulse, the supply of oxygen to the tissues by the blood, or the transmission of inherited characters by the germ-cells, we may be able to give a more or less complete physico-chemical or mechanical account of the process. But we seem to get little or no nearer to an explanation of the fact that although every one of these processes may be explicable by laws familiar in the non-living, in the living organism they are co-ordinated in such a way that none of them is complete in itself; they are parts of a whole, but the whole is not simply a sum of its parts, but is in itself a unity, in which all the parts are subject to the controlling influence of the whole. An organism, alone among the material bodies which we know, is constantly and necessarily in a state of unstable equilibrium, and yet has a condition of normality which is maintained by the harmonious interaction of all its parts. Every function of the body, if not thus co-ordinated with the rest, would very quickly destroy this condition of normality, but in consequence of the co-ordination each is subject to the needs of the whole, and normality is maintained. When the normality is artificially disturbed, all the functions of the body adapt themselves to the change, and, if the disturbance be not too great, co-operate in the restoration of the normal condition. It is in these phenomena of adaptation and organic unity and co-ordination that up to the present time the efforts to reduce the phenomena of living things to the operation of physico-chemical laws have most conspicuously failed.

From what has been said it will be evident that, fundamentally, all biological research, whether its authors are conscious of it or not, is directed towards the solution of one central problem—the problem of the real and ultimate nature of life. And the main outcome of the work of sixty years has been that this problem has begun clearly to emerge as the central aim of the science. The theory of evolution made the problem a reality, for without evolution the mystery of life must for ever be insoluble, but whatever direction biological investigation has taken, it has led, often by devious paths, to the borderland between the living and the inorganic, and in that borderland the central problem inevitably faces us.

Many suggestions for its solution have been made. On the one hand there is still, as there always has been, a considerable body of opinion that the solution will be a mechanical one—using the word mechanical in the widest sense—and that the living differs from the non-living not in kind, but only in degree of complexity. The upholders of the mechanistic or materialist theory, however, are perhaps less confident than their predecessors of the last century, for the solution in this direction has to face not only the problem of organic co-ordination already referred to, but also that of consciousness and mind. For although the study of psychology on physiological lines has made similar progress to that of other branches of physiology, it seems to approach little nearer to a discovery of the nature of the relation between consciousness in its various aspects and the material body with which it is associated. So long as this gulf remains unbridged, the possibility of a satisfactory mechanistic explanation of life seems far away.

On the other hand, there has been a revival of the ancient tendency towards what is called a vitalistic solution. A certain number of biologists, impressed by the apparent similarity between the control and co-ordination exercised by the organism over its functions and the conscious control of voluntary activity with which we are familiar in ourselves, have supposed that these things are not merely superficially similar but have a real and fundamental affinity. This does not mean that organic control is always conscious, but that there is a controlling entity, non-material in nature, which is similar in kind to the 'ego' of a self-conscious human being. They suppose that the organism is not simply material, but is a material mechanism controlled by a non-material entity the nature of which is more akin to what we mean by the word spirit than anything else of which we are accustomed to think. They are in fact dualists, and divide reality into the material and spatial on the one hand, and non-material principle or entity which may fairly be called spiritual on the other.

And, in the third place, there are those who seek a solution which denies the truth of both the preceding, and which is metaphysically idealist or monist in character. To them, if the present writer understands their attitude, matter and spirit are different aspects of one reality. In the inorganic and non-living, phenomena appear which are generalized under the laws of physics and chemistry, but the phenomena of life fall into a different category which includes the conception of co-ordination or individuality, while a still higher category is required to include the phenomena of consciousness and mind.

It is evident from this brief review that Biology in the period considered has passed through three main stages. The first of these was the acceptance of a new illuminating and unifying idea, which led to enthusiastic research in many directions for the purpose of proving and amplifying it. Very rapidly new facts, or new interpretations of facts already known, were shown to fall into line, and the evolution theory became converted from a hypothesis into something approaching a dogma. Not only the idea of organic evolution itself, but all the current beliefs about the method of evolution, and the larger speculations to which it gave rise, were widely regarded as almost indisputable, and where difficulties and inconsistencies appeared, these were supposed to be due solely to the insufficiency of our knowledge, which would soon be remedied. Then, however, as detailed knowledge increased, the voice of criticism and doubt was more frequently heard. The various branches of Biology began once more to overlap, and to join hands with chemistry and physics, and it became clear that the interpretation of life was very far from being a simple problem. And so, as with the Atomic Theory in chemistry, the present position is one of dissolution of the older ideas and of hesitation to express a fixed belief, for while Biology has a clearer vision of the problem before it than ever it had, its wider knowledge reveals the fact that the problem is far from being solved. Perhaps one of the chief results of the great increase of knowledge during the past sixty years has been to show us the immensity of the field still remaining to be explored.

FOR REFERENCE

Centenary volume on Darwin (Cambridge University Press).



X

ART

A. CLUTTON-BROCK

My subject is art and thought about art. I deal with aesthetics only so far as they concern art, that is to say I shall not attempt any purely philosophic speculations about the nature of art and I shall speak of the speculations of others, such as Croce and Tolstoy, only so far as they seem to me likely to have a practical effect upon art. My subject is the art of to-day and our ideas about it. We are beginning at last to connect aesthetics with our own experience of art and to see that our beliefs about the nature and value of art will affect the art we produce. Hence a new aesthetic is very slowly appearing; but I have to confess it has not yet appeared.

Indeed there are at present two conflicting theories of art, one or other of which is held consciously or unconsciously by most people who are interested in art at all, and both of which I think are not only imperfect but to some extent false. They are theories about the relation of the artist to the public, and because of the conflict between them and the falsity of each, we are confused in our ideas about art, and the artists are often confused in their practice of it.

The first theory has been expressed, not philosophically but with great liveliness, by Whistler in his Ten O'clock, and has had great influence both upon the thought of many people who care about art and upon the practice of artists. It is, put shortly, that the artist has no concern with the public whatever, nor the public with the artist. There is no kind of necessary relation between them, but only an accidental one; and the less of that the better for the artist and his art.

Whistler states it in the form of a New Testament of his own.

'Listen,' he says. 'There never was an artistic period.

'There never was an art-loving nation.

'In the beginning man went forth each day—some to do battle, some to the chase; others again to dig and to delve in the field—all that they might gain and live or lose and die. Until there was found among them one differing from the rest, whose pursuits attracted him not, and so he stayed by the tents with the women, and traced strange devices with a burnt stick upon a gourd.

'This man, who took no joy in the ways of his brethren—who cared not for conquest and fretted in the field—this designer of quaint patterns—this deviser of the beautiful—who perceived in nature about him curious curvings—as faces are seen in the fire—this dreamer apart, was the first artist.'

'And when from the field and from afar, there came back the people, they took the gourd—and drank from it.'

Whistler means that they did not notice the patterns the artist had traced on it.

'They drank at the cup,' he says, 'not from choice, not from a consciousness that it was beautiful, but because forsooth there was none other.'

So gradually there came the great ages of art.

'Then', he says, 'the people lived in marvels of art—and ate and drank out of masterpieces for there was nothing else to eat and drink out of, and no bad building to live in.'

And, he says, the people questioned not, and had nothing to do or say in the matter.

But then a strange thing happened. There arose a new class

'who discovered the cheap, and foresaw fortune in the facture of the sham. Then sprang into existence the tawdry, the common, the gewgaw, and what was born of the million went back to them and charmed them, for it was after their own heart.... And Birmingham and Manchester arose in their might—and Art was relegated to the curiosity shop.'

I do not think this can be a true account of the matter; for, if the people were not aware of the existence of art and did not value it at all, how came they to imitate it? One imitates only that which one values. Imitation, as we know, is the sincerest form of flattery; and you cannot flatter that which you do not know to exist.

But Whistler's account of the primitive artist is also wrong, so far as we can check it. We may be sure that, if the other primitive men had seen no value in his pursuits, they would have killed him or let him starve. And the artist, as he exists at present among primitive peoples, is not a dreamer apart. The separation between the artist and other men is modern and a result of modern specialization. In many primitive societies most men practise some art in their leisure, and for that reason are interested in each other's art. In fact they notice the cups they drink out of much more than we do. If we did notice the cups we drink out of, we should not be able to endure them. In primitive societies there are not star pianists or singers or dancers; they all dance and make music. Homer himself was a popular entertainer; he would have been very much surprised to hear that he was a dreamer apart. In fact Whistler made up this pretty story about the primitive artist because he assumed that all artists must be like himself. He read himself back into the past and saw himself painting primitive nocturnes in a primitive Chelsea, happily undisturbed by primitive critics. He is wrong in his facts, and I believe he is wrong in his theory. There is a relation, and a necessary relation, between the artist and his public; but what is the nature of it? That is a difficult question for us to answer because the relation now between the artist and the public is, in fact, usually wrong; and Tolstoy in his What is Art? tried to put it right.

What is Art? is a most interesting book, full of incidental truth; but I believe that the main contention in it is false. I will give this contention as shortly as I can in his own words.

'Art', he says, 'is a human activity, consisting in this—that one man consciously, by means of certain external signs, hands on to others feelings he has lived through, and that other people are infected by these feelings and also experience them.'

Now this is well enough as far as it goes, but it is not enough, and just because it is not enough it leads Tolstoy into error. Clearly, if art is nothing but the infection of the public with the feelings of the artist, it follows that a work of art is to be judged by the number of people who are infected. And Tolstoy with his usual sincerity accepts these conclusions; indeed, he wrote his book to insist upon them. He judges art entirely as a thing of use, moral use, and he says it can be of no use unless a large audience is infected by it. A work of art that few can enjoy fails as art, just as a railway from nowhere to nowhere fails as a railway. A railway exists to be travelled by and a work of art exists to be experienced by as many people as possible. Here are the actual words of Tolstoy:

'For a work to be esteemed good and to be approved of and diffused, it will have to satisfy the demands, not of a few people living in identical and often unnatural conditions, but it will have to satisfy the demands of all those great masses of people who are situated in the natural conditions of laborious life.'

Now this sounds plausible; but consider the effect of it upon yourself. You listen to a symphony by Beethoven; and before you esteem it good, you must ask yourself, not whether it is good to you, but whether it will satisfy the demands of those great masses of people who are situated in the natural conditions of laborious life. Tolstoy does proceed to ask himself this question about Beethoven's Choral symphony and about King Lear, and condemns them both because, he says, a Russian peasant would not understand them. But if we all obeyed him and asked this question about all works of art, we should none of us ever experience any work of art at all; for, while we listened to a piece of music, we should be wondering whether other people understood it; that is to say we should not listen to it at all. And what is this Jury of people situated in the natural conditions of laborious life who are to decide not individually but as a Jury? Who can say whether he himself belongs to them? Who is to choose them? Tolstoy chose them as consisting of Russian peasants; he, like Whistler, believed in the primitive, but for him it was the primitive man, not the primitive artist, who was blessed. In his view there would be no Jury in all western Europe worthy of deciding upon a work of art, because we none of us are situated in the natural conditions of laborious life. So we must change all our way of life or despair of art altogether. Not one of the great ages of art would satisfy his conditions. Certainly not the Greeks of the age of Pericles, or the Chinese of the Sung dynasty, or the thirteenth century in France, or the Renaissance in Italy; and as a matter of fact he condemns most of the great art of the world, including his own.

We can escape from the tyranny of Tolstoy's doctrine, as from the tyranny of Whistler's, only by considering the facts of our own experience of art. The fact that we can enjoy and experience a work of art frees us from Whistler's doctrine, because, if we can enjoy and experience it, we are concerned with it. Because of our enjoyment, art is for us a social activity and not a game played by the artist for his own amusement. We know also that the artist likes us to enjoy his art, in fact complains loudly if we do not; and we do not believe that the primitive artist or man was different in this respect. There is now, and always has been, some kind of relation between the artist and the public, but not the relation which Tolstoy affirms.

According to him the proper aim of art is to do good.

'The assertion that art may be good art and at the same time unintelligible to a great number of people is extremely unjust, and its consequences are ruinous to art itself.'

The word unjust implies that the aim of art is to do good. The artist sins if he does not try to do good to as many people as possible, and I sin if I am ready to enjoy and encourage a work of art which most people do not enjoy.

But as a matter of fact a work of art is good to me, not morally good but good as a work of art, if I enjoy it. In my estimate of the work of art I can ask only if it is a work of art to me, not if it is one to other people. I may wish and try to make them enjoy it, but if I do that is as a result of my own enjoyment of it. I can't begin by asking whether other people enjoy it; I must begin with my own experience of it, for I have nothing else to go by.

And so it is with the artist; he cannot begin by asking himself whether the mass of men will understand what he proposes to produce; he must produce it, and then trust in man, and God, for its effect. Art is produced by the individual artist and experienced by the individual man. Tolstoy holds that it is to be experienced by mankind in the mass, not by individuals; his audience is an abstraction. Whistler holds that it is produced by the individual, but for himself, and not experienced by mankind either in the mass or as individuals. Both are heretics. What is the truth?