HOW TO RAISE TURKEYS.

Keep the turkey hens tame by feeding them close to the house. Have two or three barrels in sheltered corners containing plenty of straw or leaves for them to lay in. Gather the eggs every evening, as turkey eggs are very easily chilled. Keep the eggs in a woolen cloth on end and turn them every three days. Set the first seven eggs under a chicken hen, as they get too old before the turkey hen will go to sitting. Make a board pen ten or twelve feet square and twelve or fourteen inches high. Put a coop in it and put your hen and turkeys in it. Feed the hen with corn and the turkeys soaked wheat bread (corn meal will kill them), until they are a week old (I feed five or six times a day). Then feed wheat until they are big enough to eat corn. Give plenty of fresh water in a shallow vessel. Keep the mother in the pen until they are large enough to fly over the top of the boards. Let them out awhile about the middle of the day. Shut them in at night. A turkey hen does not like to be shut up, but have a good big coop for her and she will go in. Don't let the little turkeys get their backs wet until they are feathered. The turkey hen will sit down when night comes just where she happens to be, but if you drive her home a few times she will come herself after that. Always feed them when they come home, no matter if they are full of "hoppers." Have your No. 2 pen in the orchard under an apple tree where it is shady. Have the turkey hen's pen close to the chicken hen's pen, so that when the chicken hen weans her turkeys, they will soon learn to go with the turkey hen. Give them a dose of black pepper in their feed every cold rain. And never, no never, get excited and in a hurry while working with turkeys if you don't want them to get wild and fly all over the plantation. Three or four weeks before selling, feed all the corn they will eat.

FOOD HINTS.

Restrain your desire to count your young turkeys, and let them alone for twenty-four hours after they get into this world. Remove them to a clean, airy, roomy coop, and give them boiled eggs, stale wheat bread crumbs just moistened with milk or water, "Dutch" cheese, or a mixture of all these.

For the first two weeks feed entirely with the eggs, bread, curds, cooked rice and cooked oatmeal. About the third week commence feeding cooked cornmeal; and from that on they may have any cooked food that would be suitable for chickens of the same age. Season all food slightly with salt and pepper, and twice a week add a level tablespoonful of bone meal to a pint of feed. Never feed any sour food or sloppy food of any kind, except sour milk, and never feed any uncooked food of any kind until after they have thrown out the red on their heads. Feed often, five or six times a day, until after they are three months old; then, if insects are numerous, you may gradually reduce the number of meals per day to three or even two.

After they are three months old they may be given wheat, cracked corn, etc., but not whole corn until they are five months old. Keep the coops dry and clean, and the turkeys out of the dew and rain until they are fully feathered, and have thrown out the red. Dampness and filth will kill young turkeys as surely as a dose of poison. For the first few days confine the poults to the limits of the coop and safety run; then, if all appear strong and well, give the mother hen and her brood liberty on pleasant days after the dew is off.

If they get caught out in a shower, get them to shelter as soon as possible; and if they are chilled take them to the house and thoroughly dry and warm them. See that the little turkeys come home every night. The turkey mother must, for the first few nights, be hunted up and driven home. After they are three months old, turkeys are quite hardy, and may be allowed range at all times. If turkeys that are well cared for, and have always seemed all right, show signs of drooping when about six weeks or two months old, give Douglas mixture in the drink or food, and add a little cooked meat to the food once a day.—The Practical Farmer.

ABOUT SITTING.

For an ordinary place, select from a good breed (I prefer the bronze) a large gobbler and two or three hens. As soon as the warm weather comes, place about the barn in sheltered places two or three barrels on their sides, and in them make nice nests. In these the hens will lay. Gather the eggs every day, keeping them in a cool place. When a box contains 23 eggs mark it No. 1 and begin to fill a second box, and when it contains 23 eggs mark it No. 2 and so continue. It is well to leave turkey hens on the nest two or three days, for they often lay one or two eggs after they begin to show signs of sitting.

When you have decided to sit a hen, give her a good nest and 15 eggs and at the same time give a common hen eight eggs. These, when hatched, are all to be given to the turkey hen. Never try to raise turkeys with a domestic fowl. If you have no place free of grass, you can start turkeys with difficulty. Feeding is of the greatest importance. For the first week I have found wheat bread moistened in water the most satisfactory. If you can feed them by sunrise for the first three or four weeks, you need lose hardly a bird. Each evening try and call them nearer and nearer home, so that you will not be troubled with their wandering to the neighbors'. As early as possible train them to roost high, so as to be out of danger at night. Bird dogs are often very destructive to turkeys, at times destroying a whole flock in a single night. Fatten with corn. The turkey crop ought to be one of the most profitable on our farms.

Dr. G.G. GROFF. Pennsylvania.

GRAHAM.

Turkeys want care, especially for the first two or three weeks. I feed graham and wheat bread, made by scalding the flour, making a very stiff dough, and baking in a hot oven; soak over night in cold water. I also give them plenty of young onions, cutting them up with scissors. Be careful not to let young turkeys out in the morning while the grass is wet. After the birds are two weeks old I feed wheat, but no corn until they are about a month old. I like hen mothers best, for turkey mothers are rangers, and do not take kindly to being kept in a coop. The bread will keep a week if made right, but do not soak more than will be wanted in a day, as it soon sours. I feed scraps from the table, such as potatoes and bits of meat cut very fine, but not much of the latter to young birds. I rarely lose a bird.—Mrs. E. Reith, in Homestead.

CARE AND GENERAL MANAGEMENT.

In turkey raising the one who is the most careful and attentive to the small things is the most successful. The first laying of eggs should be set under a chicken hen. The turkey hen will, after a few days' confinement, lay another batch of eggs. A good-sized hen will cover and care for ten eggs; a turkey hen, seventeen. Make a large, roomy nest of soft, fine hay—straw is too brittle and slippery. If there is danger of lice in the nest-box, sprinkle with water in which carbolic acid has been mixed in the proportion of eight drops to a half gallon of water. Don't wet the eggs with this. After the eggs have been sat on one week, sprinkle with warm water every other day, until the last week; then every day, until they hatch. Have the water clear, and use a flower or fine rose sprinkler. Let the water be of the same temperature as the eggs, which can be ascertained by slipping a thermometer under the hen for a few minutes. This softens the shells, and as a little turkey is very weak, it is helped out easily, and is stronger than if working long to get out.

Let the little turkeys get well dried and strong enough to climb around the edges of their nest before taking them off. Have a pen, say six feet square, built for them, and made tight at the sides clear down to the ground, to keep them from getting out and being chilled. Put sand and fine gravel over the ground, and cover enough of it to afford shelter at night and when it rains. They may be kept in this pen the first four or five days, then let out after dew is off, and shut up before night.

For the first few days' feed, nothing is better than clabber cheese or curd made by scalding clabbered milk until the curd separates and is cooked, then skimmed out and fed. Mix a little black pepper with this every other day. Meal must not be fed raw for several weeks, and then should be mixed with sour milk instead of water. Bake the meal into bread by mixing it, unsifted, with sour milk, and adding a little soda and pepper. Spinach, lettuce, onion tops and any other tender greens, chopped fine, are excellent food. From the time a turkey is hatched until it is ready for market it should have plenty of milk. Give them clear water to drink, for milk is a food. See that the very young ones have milk and water in quite shallow dishes, for they are in danger of getting wet if the dish is deep.

GATHER THE LITTLE TURKEYS IN

at the first signs of rain, and they will soon learn to run and fly to their coop at the first drops. Always shut them up at night, for they are early risers and will be out long before the dew is dried off. Don't pen them too near the house. Feed them at or near the same place all the time and they will learn to go there when hungry. Give them a good feed at night and they will remember to come home for it. If the morning is dry, feed lightly and let them hunt the rest in the orchard and fields. Keep the grass and weeds mowed around their pen and feeding places. Mix slaked lime in the dust for them to take their dust bath in, and sprinkle the carbolic acid and water over and around their roosting pen. Keep pails and kettles covered, for they will get drowned if they have half a chance, as they begin to fly so young. Of course a turkey hen will take her young off, and care for them after a fashion, but the safest way to make them tame is to raise them where they may be cared for. Even if the turkey hen hatches her last batch of eggs, it is a good plan to have a hen ready to take the little turkeys and slip them away at night. If she still stays on her nest give her 20 or 25 hen's eggs, and if she hatches them let her run with the chickens. They are not so tender or so easily led astray as turkeys are, nor as valuable.—Mrs. Jas. R. Hinds, in Orange Judd Farmer.

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WATER AS A THERAPEUTICAL AGENT.

By F.C. ROBINSON, M.D.

My experience in the use of water in almost every disease occurring in this climate has long since satisfied me that it is less objectionable and produces quicker and better results than any other treatment, and can be used when all other medication is contra-indicated. Drinking water should be pure, uncontaminated by animal or vegetable impurities, and given ad libitum, unless, in rare instances, it should cause vomiting or interfere with the capability of digesting food. If children are comatose or delirious, as they frequently are in typhoid fever, give water to them regularly, or force it upon them, if they refuse to take it, as I was obliged to do with a child of six years just recovering from that fever.

It is my custom to allow cold drinks of water in all cases of measles whenever patients desire it, and I am satisfied that it aids the early appearance of the rash, and certainly is cooling and grateful to the patient. Hot drinks or vile and nauseous teas are unnecessary in this disease, and should be discarded as useless, odious, and disgusting. If congestion of the lungs or any intercurrent inflammation occurs, or the rash is much delayed, a hot water bath or the old reliable corn sweat will break up the complication with amazing rapidity, and if the head is kept cool, will not generally be unacceptable to the patient.

Hot baths reduce temperature by causing free perspiration afterward, and cold packs reduce it by cooling the surface sufficiently long to reduce the heat of the blood, and, if used judiciously, seldom fail of success. I have reduced the temperature four degrees in two hours by wrapping around a child a sheet wet with tepid water, and no other covering. Cold packs are sometimes objectionable, because of their depressing effects, and should only be used to reduce high temperature and when there is no congestion or inflammation of any of the vital organs of the body.

Cold water poured in a small stream from a pitcher upon the head for five or ten minutes will often relieve headache, and is a benefit in all inflammatory brain diseases, if, at the same time, you can put the feet into hot water containing mustard or pepper.

Large enemas of warm water will care for spasmodic colic, and I have, in one instance, relieved strangulated hernia by the same method, and at another time the same result was accomplished by a large injection of warm linseed oil. I have often applied a cloth wet with cold water upon the throats of children suffering with spasmodic croup, with satisfactory results.

I have seen infants suffering with diarrhea or summer complaint, sleepless, worrying, fretting, or crying from thirst, begging for water, and the mother or nurse afraid to give it more than a teaspoonful or two at a time, saying that it vomited everything it drank as soon as taken. I have often, when visiting such cases, called for a glass of cold water, and, to the surprise of the mother, would allow it to take all it could drink, which usually would be retained, and the child would soon be wrapped in a refreshing sleep. Without medicine, a proper regulation of the child's diet would soon restore it to health again.

The spasms of children, from whatever causes, or the eclampsia from uraemic poisoning, are often readily controlled when immersed in hot water or given a hot vapor bath or corn sweat. If the convulsions of children are accompanied by a high temperature, put them into water of 100 deg. and then gradually cool it down to 68 deg. or 70 deg., and then keep them in a room of the same temperature, with little covering. If the temperature rises, repeat the treatment as frequently as necessary, and I think you will not be disappointed in the results.

Scarlet fever and diphtheria, two of the most dreaded and formidable diseases of children, are largely shorn of their terrors when, in addition to an early and thorough medicinal treatment, the little patients are bathed in as warm water as the surface will allow frequently, or for thirty minutes wrapped in a warm, wet blanket, followed by warm, dry coverings, to maintain the perspiration that such treatment usually produces. It has proved to me a valuable aid in eliminating from the blood the specific poison which causes these diseases, and I can safely recommend it to your notice and trial.

There is no disease more favorably influenced by this treatment than pneumonia, and in mild cases one daily warm bath or sweat, without medicine, will be sufficient to arrest this disease, and it is among the first things I usually order. If I find a child or infant with a temperature of 103 deg. to 105 deg., short, dry, and painful cough, dyspnoea, rapid pulse, great thirst, or vomiting, with dry crepitation in any part of the lung tissue, I order it rolled up in a blanket or sheet coming out of hot water, and in thirty minutes change it to warm, dry blankets, and soon the little fretful, worrying sufferer would rest in a quiet, peaceful sleep.—Peoria Med. Mo.

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ON THE HEALTH VALUE TO MAN OF THE SO-CALLED DIVINELY BENEFICENT GIFT, TOBACCO.

By J.M.W. KITCHEN, M.D., New York.

With perhaps the exception of heredity, the question of stimulants and narcotics in their relation to the physical welfare of the race is second to none in importance. With trifling exceptions, the whole world is addicted to their use. The universality of such use has led many to consider them a necessity to man, and that they are God's gifts to him, and, if rightly used, are of physical benefit. It may not be a perversion of judgment to consider that their widespread popular use is greatly due to the efforts of the race to gain anaesthesia for, and distraction from, those pains and punishments that are the inevitable sequence of departure from hygienic and social law on the part of the individual, his ancestry, and society in general.

The taste for these things is acquired, not natural, though the acquisition may be through hereditary influence. An idea is held by a majority of even fairly intelligent individuals that there is a justifiable, harmless, and even beneficial use of these substances by the general public, though acknowledging that beyond a certain indefinite line this use becomes an abuse.

I believe that there may occasionally be cases in which the physical benefits derived from their use outweigh the injury they inflict, but I think this use is very much less than is generally supposed, and if we can judge from the preponderance of evil effected by such use, these substances ought to be considered as the materialized curses of God rather than as beneficent gifts. The prevalent idea as to the beneficent nature of these substances I consider to be a delusion that can only be explained upon the hypothesis that there is a widespread lack of appreciation of the fact that, though they may have an immediate pleasant and agreeable effect upon the body, their injurious effects are cumulative, and are usually ultimate, and so distant as to be difficult of direct connection with their cause to ordinary observation. The more moderate the use of these substances, the more remotely is the effect removed from the cause and more difficult of detection. That the ordinary habitual, so-called moderate use of stimulants and narcotics, such as tea, coffee, tobacco, and alcohol, is, in the vast majority of cases, really an abuse, is a proposition that I think should be admitted by all who have given the subject an unbiased study.

The idea that the user of tobacco and other injurious substances will be cognizant of the injury inflicted by habitual use in moderate or even excessive amounts is an undoubted fallacy. The daily, weekly, or monthly injurious effect may be entirely unobservable to even trained physicians, and yet the ultimate cumulative effect may be fatal. I can instance numerous cases of physicians directly fatally injured by the use of alcohol, who have never had the slightest cognizance of the fact; and I can also instance cases of grave disease from the use of tobacco where the patients never have believed that tobacco has been the cause of their troubles, even after a unanimous opinion to that effect has been expressed by a number of competent medical advisers. The habitual consumption of opium, in doses of any amount, is generally admitted by most people to be physically injurious outside of its strict medicinal application. Moderate indulgence in alcohol as a beverage is beginning to acquire a very widespread evil reputation. But how about tobacco? Tea and coffee we can confidently leave to the consideration of a somewhat remote posterity of a considerably advanced intelligence and elevated hygienic ideals.

The relation of tobacco to the physical welfare of man can only be fairly estimated by viewing the subject in its broadest aspect; by considering its effects upon the race as a whole rather than in individual cases; by taking into consideration economical and other social conditions that at first sight might be considered as having little relevancy to the medical side of the subject. But there can be no just consideration of the matter otherwise. The direct deleterious effects of the immoderate use of tobacco are readily observable; but the great bulk of the evil physical effects due to the moderate use of this plant are of an intermediate nature and not directly noticeable; nevertheless, they are real, and worthy of medical attention. The plainly marked results following the use of tobacco in relatively large amounts seem to be due to quick and extreme interference with nutrition, and a diminution of function of all kinds, which may be represented by anything from a slight decrease of appetite and digestive ability up to a complete loss of function of almost any important organ. Tobacco has stimulating as well narcotic properties, but as ordinarily used its stimulating effect appears to be slight as compared with its narcotic influence. In this respect it differs from alcohol, the use of which, owing to the usual method of introduction in large amounts through the stomach, produces directly, by stimulation, readily noticeable structural changes. But with tobacco the direct evil results are mostly of a functional character, and are more generally diffused, owing to the usual slow manner of introduction into the body. These two properties have an effect upon the body in moderate use as well as in immoderate use, the effect being simply in proportion to the quantity used, though the effects of moderate use may not be measurable by ordinary means. It is easy to see the effects of large amounts of tobacco in the stunted growth of adolescents; in functional cardiac disorders; in intellectual sluggishness, loss of memory, and color blindness; in loss of appetite, and other neuroses of motion, and marked blunting of various functions of sensation, and in degeneracy of descendants; but that lesser evils are produced must be proved mostly by inference, circumstantial collateral evidence, and analogy.

The greater evils that are the outcome of a moderate use of tobacco are probably due to prolonged slight interference with nutrition, and consequent general decrease of vitality, which renders the individual more susceptible through indirect influence to the invasion of disease, and which lessens the capacity for productive effort.

It is of course difficult, and perhaps even impossible, to accurately estimate the value of tobacco to the race; but let us glance at the pros and cons, and then each one can roughly estimate for himself. Tobacco may be used medicinally, but it is a dangerous and uncertain remedy, and it probably has not one medicinal use that cannot be more suitably met by other remedies. One can readily imagine easier digestion as the result of the sedative influence of the after-dinner cigar upon a disquieted nervous system, especially if the coincident irritation of alcohol and coffee have need of correction; but it can also be imagined that in most of such cases the remedy has been the cause of and will further increase the disordered condition, and that nutrition of deficiently nourished nerve tissue is rationally indicated rather than partial narcotization. There then remains, so far as I can see, the solace of moderate anaesthesia and, occasionally, of occupation for idlers, as the only items that can be placed to the credit of tobacco. There certainly are individual cases where such usage may be more provocative of physical benefit than evil, but, before judging for the race as a whole, compute the other side of the question.

Tobacco injures the general health of the public through the economic loss caused by its consumption. The people of our country spend annually over seven hundred millions of dollars for tobacco—twenty per cent. more than is spent for bread. This sum represents only a minor part of the cost of the tobacco habit to the country. The crop is immensely exhaustive to the soil. Its culture has blighted whole sections of fertile territory. In the time consumed by the producer and the trader in its production, manufacture, and sale, and by the consumer in its use, and by the general interference with vital activity and consequent decreased productive capacity, there is represented an almost unimaginable sum of money. Certainly the people at large are not so well fed both as to quantity and quality, or so thoroughly clothed, or so hygienically housed that they can afford this gigantic economic waste.

There can be little doubt that if the people had sufficient intelligence and moral strength to taboo tobacco, this comparatively senseless outgo would be largely devoted to supplying these and other necessities of an exalted health status.

Tobacco injures health through its moral effects. The tobacco habit is certainly a dirty and frequently a disgusting habit, and encourages other dirty practices. Its use tends to make men cowardly, irritable in temper, and low in spirits. It blunts ideas of purity and courtesy, leading to invasion of the rights of others. It is presumed that few medical men would visit a delicate, sensitive patient after saturation with the "fragrant" effluvia of onions, but thousands whose systems are saturated with nicotine and who reek with nauseating odor do not hesitate to inflict their presence on sick or well. The time will come when the tobacco user will not be allowed to poison the atmosphere that is the common property of the public—will not be allowed to force the inhalation of nicotine upon the general public, to say nothing of being allowed to poison the infants and women in his own family. What would be said of a man who introduced poison in any degree into the food or drink of his child? Is the poisoning of the household atmosphere by the ignorant, thoughtless, or selfish smoker morally more defensible? Tobacco injures health through hereditary influence. The tobacco user begets, more certainly than the non-user, puny children with disordered nervous conditions. Luckily for our race, the women, who have the most important prenatal influence in guarding its physical well-being, are practically non-users of the plant. The general health status of the race is improving, not because the use of tobacco or the indulgence in other questionable practices is harmless, but because, among other things, of the great advance in general intelligence and knowledge of hygienic law.

A person, or the public in general, may practice an injurious habit, and yet more than counteract its influence by opposing beneficial practices.

Horace Greeley said, "Show me a drunkard who does not use tobacco, and I will show you a white blackbird." In this country, where dietetic drinking habits are not common in the family, the weakening of moral fiber by indulgence in tobacco is usually the introduction into the round of vicious indulgences, and thus directly or indirectly affects health. Smoking induces dryness of the mucous membrane of the mouth and consequent thirst. The partially paralyzed nerve terminals want something more stimulating than water to afford relief. Furthermore, blunted appetite induces deficient nutrition, and consequently there is a call for some "pick-me-up;" hence we find that the use of tobacco tends to the habitual use of alcoholic beverages, and there are very few habitual users of alcohol who escape without structural injuries to the body as well as perversion of its functions. Decrease of vital activity in all the tissues of the body marks the use of tobacco. The tendency is toward functional paralysis, though occasional signs of stimulative irritation are to be noticed, especially in the respiratory passages. The interference with intellectual activity is marked. It is said that during a period of fifty years no tobacco user stood at the head of his class in Harvard. The accumulated testimony of investigating observers is conclusive that, other things being equal, users of tobacco, in schools of all grades, never do so well in their studies as non-users.

One head of a public school said he could always tell when a boy commenced to use tobacco by the record of his recitations. Professor Oliver, of the Annapolis Academy, said he could indicate the boy who used tobacco by his absolute inability to draw a clean, straight line. The deleterious effects of tobacco have become so clearly apparent that we find its sale to minors is prohibited in France, Germany, and various sections of this country. It is somewhat a question if, at the present time, the race is not doing itself more injury by its use of tobacco than it is with alcohol, because of its more universal use, particularly by youth, and because of the respectability of the habit, which comes of its use by a certain intelligent part of the race, including teachers of morals and physics, and even temperance reformers. There is a widespread sentiment in existence that it is not a respectable thing to be even partly paralyzed by alcohol, but how few there are who consider narcosis as in any way connected with the use of tobacco. Its effect is more diffused and masked, and is not so acutely serious in individual cases, but through its interference with vital activity, tobacco is probably more generally injurious to the race than alcohol.

The editorial fiat of "too long" prevents a full exposition of the subject, but, in closing, let me say I hear millions of tobacco users ask, "Why, then, was this plant given to man, if its general effects are so decidedly evil?" The question presupposes design in creation. Without subscribing to this theory, or pretending to have solved the mystery of the presence of evil in the world, the answer may be suggested that the overcoming of many seductive evils becomes to man a means of his progressive higher development. Of one thing I am convinced, that the physical development and welfare of man is interfered with in strict sequence to his consumption of substances that are unnecessary for his nutrition—stimulants and narcotics inclusive.—Medical Record.

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ACETIC ACID AS A DISINFECTANT.

Dr. F. Engelmann, in Cent. f. Gyn., claims that acetic acid possesses equally as good antiseptic properties as carbolic acid; in fact, that it is to be preferred, as it is completely harmless, even if used in concentrated solutions, and that it is a valuable haemostatic, an advantageous addition particularly in obstetrics. Another important property is its ease of transition into the tissues, which, according to Engelmann's experiments, is by far greater than that of all the other antiseptics. Of bichloride it is well known that it forms an insoluble combination with albumen, and can therefore act only on the surface, while acetic acid extends into the deeper tissues with ease.

Acetic acid also affects the metal of the instruments, but not as severely as the bichloride; the forceps, for instance, may be placed for a quarter of an hour in an irrigator filled with a three per cent. solution of acetic acid without being injured.

A pleasant effect of acetic acid is that it softens and lubricates the skin. The author generally used a three per cent. solution; at times he has made use of a five per cent. solution, which would easily cause a painful burning at sore places, so that he only used the latter strength in septic cases, as the three per cent. solution proved to be a satisfactory antiseptic for general purposes.

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COUNTER-IRRITATION IN WHOOPING COUGH.

By G.F. INGLOTT, M.D.

To combat this often distressing disease I have tried the administration of several medicines, namely, bromide of potassium, asafoetida, valerian, morphine, belladonna, etc., and I have very closely watched their effects, but none of them proved of much use. Having observed, however, that during the late cholera epidemic some of the patients admitted into the hospital under my medical charge slept well, had their anxiety improved, and some of them ultimately recovered, after the application of a strong counter-irritation of the pneumogastric nerves in the neck, namely, between the mastoid process and the angle of the lower jaw, I tried the same treatment on whooping patients, and I have no hesitation in stating that the result was very satisfactory. I may quote one single case of the many I have had under treatment.

A boy, aged twelve years, of weak constitution, was suffering from frequent and intense attacks of whooping cough. At a time the fits were so vehement that blood came out of his eyes and mouth. The case was a severe one, and I thought it would very likely end fatally. I prescribed several medicines, and even subcutaneous injections of morphine, but without any avail. I then tried for the first time the counter-irritation on both sides of the neck, and this means acted like magic. In four or five days the patient recovered, and was able to go to school. Since that time I have been applying the same treatment, either on the right side only or on both, with the greatest benefit.—Br. Med. Jour.

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DEVELOPMENT OF THE EMBRYO.

At a recent meeting of the Physical Society, Berlin, Prof. Preyer spoke on reflexes in the embryo. His researches extended over many classes of animals. As representing mammals, guinea pigs were chiefly used; and for reptiles, snakes; while in addition the embryos of fishes, frogs, mollusks, and other lower animals were also employed. But of all animals birds are most suitable for embryological observations, inasmuch as with due precautions the development of one and the same individual can be followed for a considerable time. Birds' eggs can be incubated in a warm chamber, and by removing a portion of the shell and replacing it by an unbroken piece from another egg, it becomes possible to follow the daily development of the chick and to experiment upon it. As early as the ninetieth hour of incubation, spontaneous "impulsive" movements may be observed, taking place apparently without any external stimulus as a cause, and at a time when no muscles or nerves have as yet been developed. After the occurrence of these spontaneous movements, and at the earliest on the fifth day of incubation, movements are observed to result from the application of mechanical, chemical, and electrical stimuli. In order to observe these the eggs must be allowed to cool down until all spontaneous movements have ceased. From the tenth to the thirteenth day more complicated and reflex actions occur on the application of stimuli, as, for instance, movements of the eyelids, beak, and limbs; and if the stimuli are strong, reflex respiratory movements. These reflexes make their appearance before any ganglia have become differentiated. Prof. Preyer considered himself justified in concluding from this that ganglia are not essential for the liberation of reflex actions. He intends, on some future occasion, to give a more detailed account of these experiments, and of the conclusions which may be drawn from them. In the discussion which ensued the conclusions of the speaker were contested from many sides.

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IRIDESCENT CRYSTALS.[1]

[Footnote 1: Abstract of the Friday evening lecture delivered by Lord Rayleigh, F.R.S., at the Royal Institution, on April 12, 1889.]

By LORD RAYLEIGH.

The principal subject of the lecture is the peculiar colored reflection observed in certain specimens of chlorate of potash. Reflection implies a high degree of discontinuity. In some cases, as in decomposed glass, and probably in opals, the discontinuity is due to the interposition of layers of air; but, as was proved by Stokes, in the case of chlorate crystals the discontinuity is that known as twinning. The seat of the color is a very thin layer in the interior of the crystal and parallel to its faces.

The following laws were discovered by Stokes:

(1) If one of the crystalline plates be turned round in its own plane, without alteration of the angle of incidence, the peculiar reflection vanishes twice in a revolution, viz., when the plane of incidence coincides with the plane of symmetry of the crystal. [Shown.]

(2) As the angle of incidence is increased, the reflected light becomes brighter and rises in refrangibility. [Shown.]

(3) The colors are not due to absorption, the transmitted light being strictly complementary to the reflected.

(4) The colored light is not polarized. It is produced indifferently, whether the incident light be common light or light polarized in any plane, and is seen whether the reflected light be viewed directly or through a Nicol's prism turned in any way. [Shown.]

(5) The spectrum of the reflected light is frequently found to consist almost entirely of a comparatively narrow band. When the angle of incidence is increased, the band moves in the direction of increasing refrangibility, and at the same time increases rapidly in width. In many cases the reflection appears to be almost total.



In order to project these phenomena a crystal is prepared by cementing a smooth face to a strip of glass whose sides are not quite parallel. The white reflection from the anterior face of the glass can then be separated from the real subject of the experiment.

A very remarkable feature in the reflected light remains to be noticed. If the angle of incidence be small, and if the incident light be polarized in or perpendicularly to the plane of incidence, the reflected light is polarized in the opposite manner. [Shown.]

Similar phenomena, except that the reflection is white, are exhibited by crystals prepared in a manner described by Madan. If the crystal be heated beyond a certain point the peculiar reflection disappears, but returns upon cooling. [Shown.]

In all these cases there can be little doubt that the reflection takes place at twin surfaces, the theory of such reflection (Phil. Mag., Sept., 1888) reproducing with remarkable exactness most of the features above described. In order to explain the vigor and purity of the color reflected in certain crystals, it is necessary to suppose that there are a considerable number of twin surfaces disposed at approximate equal intervals. At each angle of incidence there would be a particular wave length for which the phases of the several reflections are in agreement. The selection of light of a particular wave length would thus take place upon the same principle as in diffraction spectra, and might reach a high degree of perfection.

In illustration of this explanation an acoustical analogue is exhibited. The successive twin planes are imitated by parallel and equidistant disks of muslin (Figs. 1 and 2) stretched upon brass rings and mounted (with the aid of three lazy-tongs arrangements) so that there is but one degree of freedom to move, and that of such a character as to vary the interval between the disks without disturbing their equidistance and parallelism.

The source of sound is a bird call, giving a pure tone of high pitch (inaudible), and the percipient is a high-pressure flame issuing from a burner so oriented that the direct waves are without influence upon the flame (see Nature, xxxviii., 208; Proc. Roy. Inst., January, 1888). But the waves reflected from the muslin arrive in the effective direction, and if of sufficient intensity induce flaring. The experiment consists in showing that the action depends upon the distance between the disks. If the distance be such that the waves reflected from the several disks co-operate,[2] the flame flares, but for intermediate adjustments recovers its equilibrium. For full success it is necessary that the reflective power of a single disk be neither too great nor too small. A somewhat open fabric appears suitable.

[Footnote 2: If the reflection were perpendicular, the interval between successive disks would be equal to the half wave-length, or to some multiple of this.]

It was shown by Brewster that certain natural specimens of Iceland spar are traversed by thin twin strata. A convergent beam, reflected at a nearly grazing incidence from the twin planes, depicts upon the screen an arc of light, which is interrupted by a dark spot corresponding to the plane of symmetry. [Shown.] A similar experiment may be made with small rhombs in which twin layers have been developed by mechanical force after the manner of Reusch.

The light reflected from fiery opals has been shown by Crookes to possess in many cases a high degree of purity, rivaling in this respect the reflection from chlorate of potash.

The explanation is to be sought in a periodic stratified structure. But the other features differ widely in the two cases. There is here no semicircular evanescence, as the specimen is rotated in azimuth. On the contrary, the colored light transmitted perpendicularly through a thin plate of opal undergoes no change when the gem is turned round in its own plane. This appears to prove that the alternate states are not related to one another as twin crystals. More probably the alternate strata are of air, as in decomposed glass. The brilliancy of opals is said to be readily affected by atmospheric conditions.

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