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tongue rather dry, the appetite defective. Increased ingestion of water caused an acceleration of the total metamorphosis of matter, which in some instances manifested itself more through the skin than through the other organs of excretion; in most cases, however, principally through increased flow of urine containing an increased amount of solid constituents; the increase was largest as regards urea, after which follow chloride of sodium, phosphoric acid, and sulphuric acid. These phenomena were accompanied by loss of weight of the body. On the days succeeding the increased ingestion of water the excretions were diminished, and the body gained weight.

On the Physiological Action of Strychnia and Brucia. By Dr. HARLEY, Professor of Practical Physiology in University College, London. ("Lancet," June 7 and 14, and July 12, 1857.)

The investigations of Dr. Harley upon the physiological action of strychnia and brucia are calculated to shed much light upon the mode in which muscle is affected by chemical and analogous agencies.

These investigations, which are of extreme importance in a therapeutical as well as in a physiological point of view, show very clearly that these poisons do not cause death by exhaustion, or by suffocation, arising either from closure of the glottis, or from spasm in the walls of the chest, but "by destroying the powers of the tissues and fluids of the body to absorb obygen and give off carbonic acid." It is argued that death is not caused by exhaustion, because it cannot be supposed that the system can be fatally exhausted in less than two minutes. It is proved that death is not caused by closure of the glottis, because the animal dies as speedily when its windpipe has been freely opened before the administration of the poison. It is proved, moreover, that spasm in the walls of the chest is not the cause of death, because artificial respiration can be performed without averting or even deferring the fatal issue. At the same time, the animal seems to "feel a want of oxygen," and that this is one cause of death Dr. Harley shows very plainly by the examination of its blood. In this examination Dr. Harley uses the fresh blood of the calf. Of this blood he takes two portions, and mixing a small quantity (0.005 grammes) of strychnia with one, he ascertains the amount of oxygen absorbed and carbonie acid given off by examining the composition of air that has been left in contact with each. In each case the blood is thoroughly saturated with oxygen by shaking it with fresh quantities of air; and after this it is corked up in a graduated tube with 100 per cent. of ordinary air, and frequently agitated for the next twenty-four hours. At the end of this time, the air contained in the tube is analyzed by Bunsen's method, and the following is the result arrived at:

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The air, that is to say, which had been in contact with the blood containing strychnia has more oxygen and less carbonic acid than the air which had been left in contact with simple blood; and thus it would appear that less oxygen has been absorbed and less carbonic acid given off by the blood containing strychnine. When brucine is used instead of strychnine, the only difference in the result is one of degree :

was 86, and my respirations were sixteen in a minute. At 1.50 o'clock my pulse had fallen to 80, or the standard at which it was found before the commencement of the experiments.

"Thus within the space of one hour I took rather more than one drop of pure glonoine, which is the amount contained in eighty drops of the solution spoken of by Mr. Field. This would appear conclusive as to the fact that whether in weak solution (1 in 100) as employed by the homoeopathists, or in a strong solution (1 in 6) glonoine does not produce the effects which have been ascribed to it; and that, contrary to what has been stated by Gmelin and implied by Mr. Field in his recent communication, it may be taken with impunity in considerable quantity. Whether the acceleration of the pulse which was observed in the first instance was attributable to the effect of glonoine, is a question which requires further experiments to determine. My own impression is, that it was purely the effect of the nervousness or excitement resulting from the experiments in which we were engaged, for had it been otherwise it is not probable that the pulse would have fallen to its natural standard within so short a period after taking the larger doses. The fulness in the head may have been attributable in part to the same cause, but some discomfort about the head, not amounting to headache, continued for several hours afterwards, and I cannot help thinking that it is fairly referable to the effect of the glonoine I had taken. I will only add, that for some weeks I had been suffering from slight bronchial irritation, with frequent expectoration of thick mucus, and that since I swallowed the glonoine I have not had occasion to cough or expectorate."

3. The glonoine used by Dr. Harley was procured at a homoeopathic pharmacy, and of the same strength as that used by Mr. Field.

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I began," he says, "by touching my tongue with the cork moistened with the solution; but experiencing no effect beyond that which usually follows the application of alcohol or ether to the tongue, I boldly put a couple of drops in my mouth. At first I felt a kind of sweet and burning sensation, and soon after a sense of fulness in the head, and slight tightness about the throat, without, however, any nausea or faintness. After waiting a minute or two these effects went off, and I could not help thinking that they were partially due to imagination. Determined to give the thing a fair chance, I swallowed five drops more, and as these did not cause any increased uneasiness, I took, in the course of a few minutes, other ten drops of the solution. Being at the time quite alone, I became somewhat alarmed lest I should have taken an over-dose, and very soon my pulse rose to above 100 in the minute. The fulness in the head, and constriction in the throat, I thought was more marked than after the previous dose. In a minute or two, however, my courage returned, and the pulse soon fell to 90. The fulness in the head lasted some time, and was followed by a slight headache. Next day I repeated the experiment upon myself by taking ten-drop doses, and finding no bad effects to result from them, I tried the substance on some of my friends, without saying what sensations might be expected to arise from it: and I may cite the following as a good example of an experiment unaffected by imagination :

"To Dr. von F., a strong, healthy gentleman, aged twenty-six, respirations twenty-eight, and pulse eighty-four in the minute, I gave ten drops of the solution. After waiting five minutes without witnessing any effect, I administered other eighteen drops of the glonoine in a little water. In about a quarter of an hour the pulse was noticed to be slower; this, however, was, no doubt caused by him sitting quite still. The respirations remained as before, and neither fulness in the head, nor constriction in the throat was complained of. Upon the tongue of another gentleman (a medical man), who was equally ignorant of the contents of Mr. Field's communication, I allowed two drops of glonoine to fall; after waiting five minutes without any peculiar sensation being felt, I gave him eighteen drops of the solution, and in five minutes more, as there was still not the slightest effect observable, I again gave him other eighteen drops. The pulse and respirations were carefully watched during a quarter of an hour longer; but as absolutely nothing was either felt or observed, my friend went home. Having been thus unsuccessful in obtaining any decided effects from

"6. The heart and muscles of frogs poisoned with urari may be paralyzed by antiar.

7. From all this it may be deduced that the antiar principally acts upon the muscular fibre and causes paralysis of it.

"So much for this time. My experiments with the antiar upon warmblooded animals have only begun, and I am not yet able to draw any conclusion from them. As soon as this will be possible, I shall take the liberty to submit them to the Royal Society, together with the results of my experiments with the upas teinté, which poison I had also the good fortune to obtain through the kindness of Sir Benjamin Brodie and Dr. Horsfield. With regard to the antiar, I may further add that experiments made independently, and at the same time, by my friend Dr. Sharpey with this poison, have conducted to the same results as my own."

On the Injection of Urea and other Substances into the Blood. By Dr. W. A. HAMMOND, Assistant Surgeon United States Army. ("North American Medico-Chirurgical Review," March, 1858.)

The principal object in undertaking the experiments detailed in this paper, is that of deciding upon the correctness of the theory advanced by Frerichs explanatory of uræmic intoxication. As is well known, this distinguished author regards the symptoms of blood poisoning, so frequently present in Bright's disease, as not directly depending upon the presence of urea in this fluid, but as being caused by its conversion, through the agency of a ferment, into carbonate of ammonia.

Frerichs performed two series of experiments, which he regards as tending to sustain his hypothesis. In the first series he injected a solution of urea into the blood of animals whose kidneys had been previously removed. In from an hour and a quarter to eight hours they became restless, and vomited. Ammonia was detected in the expired air, and simultaneously convulsions ensued. Death occurred in from two hours and a half to ten hours from the commencement of the experiment. Ammonia was found in the blood, the contents of the stomach, and in the bile and other secretions.

In the second series a solution of carbonate of ammonia was injected. Convulsions ensued almost immediately, and were quickly followed by stupor. The respiration was labored, and the expired air was loaded with ammonia. substance, however, gradually disappeared, and the animals recovered their

senses.

This

Frerichs offers no explanation of the nature of the ferment which he conceives to be necessary to produce uræmic poisoning, nor does he even attempt to demonstrate its existence, except indirectly, through the experiments above cited.

While admitting the facts set forth by these experiments, Dr. Hammond differs with Frerichs in his theory. Ammonia has often been met with as a constituent of the expired air of healthy individuals. He has himself frequently detected it in such cases; it has been demonstrated to be constantly present in the blood; and Frerichs' own experiments (those of the second series) show that it was not capable of causing death even when injected directly into the circulation, and when its presence in the blood was evidenced by its being exhaled in large quantity from the lungs.

The fact that in the first series of investigations the kidneys were extirpated, while in the second the animals were unmutilated, while different substances were used in each, prevents our drawing any comparative conclusions from the results obtained.

The experiments to which the present paper relates consisted of two series. In the first the substance was injected into the blood of the sound animal; in the second the kidneys were previously extirpated. The two series were, as far as possible, alike in every other respect. The substances injected in both series were urea, urea and vesical mucus, carbonate of ammonia, nitrate of potash, and sulphate of soda.

Dr. Hammond's conclusions are:

1st. That urea (simple and combined with vesical mucus), carbonate of ammonia and sulphate of potash, when injected into the blood vessels of sound animals, do not cause death.

2d. That nitrate of potash, when thus introduced, is speedily fatal.

3d. That death ensues from the injection of any of the foregoing named substances into the circulation of animals whose kidneys have been previously extirpated.

4th. That in neither case dose urea when introduced directly into the circulation, undergo conversion into carbonate of ammonia.

The Histology of the Supra-renal Capsules. By GEORGE HARLEY, M. D., Lecturer on Practical Physiology in University College, London. ("Proceedings of the Royal Medical and Chirurgical Society," December 8, 1858.)

The author begins this paper by pointing out that the supra-renal capsules could not properly be said to diminish in proportionate size and activity of function with advancing years. He also exhibited several preparations of supra-renal capsules taken from individuals of different ages, to prove that their development proceeded at a certain ratio after birth. He moreover states that as they did not become proportionally more atrophied in old age than many of the other organs, it might naturally be supposed that they had a certain function to perform in adult as well as in foetal life. Dr. Harley then calls attention to the great variety of size and shape of the supra-renal capsules throughout the vertebrata, and afterwards proceeded to point out the appearances presented to the naked eye by healthy supra-renal capsules. He denies the existence of any large cavity in the centre of the healthy human supra-renal capsule, and said that when such was found it was the result either of accidental rupture of the medullary substance, or as the effect of disease. He points out, however, the existence of a number of small sinuses in the centre of the organ. Dr. Harley says that the cortical and medullary portions of the supra-renal capsules, which are so different in color, have equally distinct microscopical characters. The former, which constitutes the greater part of the organ, consists of a number of cells arranged in irregularly sized rows in a fibro-areolar matrix; the rows of cells appearing like a number of dark-yellow columns placed perpendicularly to the surface. The cells when examined individually are seen to be composed of a homogeneous cell-wall, filled with granules, pigment, and some fat-globules. Each cell possesses a well-marked nucleus, although it is not always visible without the employment of reagents. The easiest way to demonstrate the existence of a nucleus, the author said, was to color the cells with carmine. When floating free in the field of the microscope the cells appear irregularly round; but when grouped together they have a somewhat polygonal form. The cells are arranged in a number of larger and smaller masses, which are placed in regular rows, and thus give rise to the columnar appearance. In some cases a column is composed of several cellmasses of different lengths, placed end to end. In others it consists almost entirely of one long cell-mass. Each column, as well as each cell-mass, is separated from the others by delicate fibrous tissue, in which are imbedded the vessels and nerves. Sometimes the cell-masses present the appearance of long tubes, inclosing a single straight row of quadrilateral cells. Each cell-mass is closed at the extremities, and is surrounded by a delicate homogeneous membrane. The dark, slate-colored medullary substance of the supra-renal capsules has a very different structure from that just described. It is composed of a network of fibres, in the meshes of which are a number of large nucleated cells, which has been described by various writers as ganglion-corpuscles. Dr. Harley thinks, however, that these, like the cells in the cortical substance, are true secreting cells. The supra-renal capsules are very freely supplied with blood vessels. Their course and distribution were minutely described.

The author concluded his communication by making a few remarks on the supposed function of the organ, in the course of which he observed that in the supra-renal capsules of the frog he had found blood corpuscles in various

stages of development. Each point of importance in the paper was fully illustrated by diagrams and microscopical preparations.

On the Functions of the Thyroid Body. By Dr. PETER MARTYN. ("Proceedings of the Royal Society," 1858.)

After referring to the form, situation, connections, and internal structure of the thyroid body, its large supply of blood, and its capability of sudden alterations of bulk, the author briefly adverts to the unsatisfactory explanations which have been offered as to its function, and then proceeds to state his own views, as follows:

"The upper part of the trachea, the larynx, and the passage of the fauces and mouth, constitute the organ of voice; the two former are the essential or voicing part, as mechanicians call it, that which produces the tone. The larynx and trachea-taking a share in other functions and being associated by juxtaposition and attachment with contiguous organs are always pervious and open for respiration; lengthen and shorten, fall and rise with the oesophagus in deglutition, and bend and turn with the universal motions of the head and neck.

"To admit of this great mobility and flexibility, a certain structure is necessary. The larnyx is a triangular box, inclosing the apparatus of the chordæ vocales; its two cartilaginous sides or alvæ, diverging from the front, are not fixed but free at the back, being completed by soft parts; the trachea is composed of a succession of incomplete cartilaginous hoops or rings lying apart, the back and intervals being made up and the tube completed by soft membrane.

"Now the structure of a wind instrument, such as that of the human voice, requires the opposite properties. It must be rigid, tense and inflexible. The qualities of the tone will be in exact proportion to these properties. How then is the soft, slack and flexible vocal tube rendered thus rigid, tense and inflexible, and fit to produce pure tone? The muscles of the larynx, the thyro-hyoid and sterno-thyroid, merely raise or lower, or fix it in any position: not lying on, or being parallel to, but diverging from the vocal tube, they cannot affect the object referred to. It appears to me that the thyroid body is provided for this purpose. The act of uttering a tone or of speaking stops the return of the blood from that organ, distends and renders it tense, and from the nature of its attachment round the top of the trachea and on the free sides of the ala of the larynx, renders them fixed, firm and tense also. This effect is aided by the aforesaid muscles, the thyroid body being interposed and giving them more advantageous mechanical action. This tension may be in any degree, and on energetic speaking or singing, the increased size of the part and the fulness of the collateral veins may be seen. This is the reason of its large supply and free distribution of blood. An instance of the want of this tension in an instrument may be seen in the bagpipe, where the porte-vent is attached to the chanter or voicing part by a flexible joint or by leather, and the tone is in consequence squeaking and uncertain.

"Besides thus giving rigidity, firmness and tension to the organ of voice, the thyroid body also acts in another capacity-as a loader. In most musical instruments, loaders are used to render the vibrations slower and longer, and the tone in consequence fuller, louder and deeper. They compensate for want of size and space, and give to a small instrument, or to a small vibrating or voicing part of an instrument, the power and quality of a large one. The human organ of voice is eight inches long, and has the same power as, and better quality of tone than, the instrument that most nearly approaches it-the French horn, which is nine feet, or the 'vox humana' pipe of a moderate sized organ, which is from four to eight feet long. The economy of size in the human organ has always been wondered at, but never, that I know, explained. Besides the thyroid body, another part, the structures of which I shall describe on another occasion, aids in this admirable economy. The nearer mechanism of human design approaches to perfection, the more it resembles similar structures in animal mechanics. The base of all stringed instruments and musical

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