caused in the defibrinated blood of oxen by the admixture of carbonic oxide. As well the arterial as also the venous blood of oxen, when shaken with this gas, becomes bright red-the redness differing, however, from that of the normal arterial blood by being possessed of a violet hue. Neither the action of carbonic acid, nor that of atmospheric air, nor that of commencing decomposition, effect a change in the colour produced by the carbonic oxide. From these facts the author infers that the gas is not only absorbed by the blood, but enters into a chemical combination with the hæmato-globulin, by which circumstance the blood-globules lose their virtue of being the bearers of oxygen.

Hoppe exposed various animals to a considerably diminished atmospheric pressure, by means of the air-pump. The symptoms exhibited by different classes of animals were very different. Frogs and a blind-worm bore the reduction of pressure to 30 millimetres mercury, and below this, without dying: swelling up of the whole body, expulsion of gas through mouth and anus, and syncope, were the principal symptoms. Rats and young cats became suddenly convulsed at a pressure of 50 millimetres; the convulsions were soon followed by syncope. Admission of air in this state restored them to apparent health, but these animals died at the reduction of the pressure to 40 millimetres. In guinea-pigs, sudden diminution of pressure to 80 millimetres caused convulsions and syncope. Two swallows became convulsed when the pressure was not lower than 130 millimetres, and died at the reduction to 125 millimetres. All the animals killed by low pressure exhibited small bubbles of air in the large vessels and in the right ventricle, while no air was found in the bloodvessels of frogs examined in the state of syncope. The author directs attention to the facts, that birds die before the pressure is reduced to the boiling point of the blood, that mammalia die at a pressure slightly exceeding the boiling point, while amphibia survive the reduction to the boiling point. Hoppe ascribes the symptoms caused by low pressure, not to the want of oxygen in the blood, but to the development of gas within the vessels: the sudden death is considered as the effect of the blocking-up of the pulmonary capillaries by this gas. The point at which the development of gas takes place, appears to depend on the preceding degree of pressure on the temperature of the animal, and the greater or smaller power possessed by the blood of absorbing gases-which power is probably dependent on the proportion of blood-globules.

Regarding the influence of increased pressure, the author offers only a few experiments. An increase of 150 millimetres (i.e., to about 908 millimetres) was borne by a pregnant rat without any symptoms of uneasiness. A priori, it is to be supposed that the blood must show an increased power of absorbing gases, augmented heat, &c. Sudden diminution of the previously-increased pressure of air probably leads to development of gas within the vessels, and the pathological phenomena just mentioned. Hoppe is inclined to attribute cases of sudden death without anatomical lesion, observed in coal-mines, to this

cause.

If we compare with these results Valentin's observations on marmots during the state of hybernation, we find that this author, too, witnessed symptoms of great uneasiness when the reduction of the pressure was carried to below 10 millimetres, which was equal to about of the pressure of the surrounding air; but, after some time, the animals became again quiet, and continued to sleep. On further reduction to of the external pressure, the symptoms exhibited by the animal, after having been for more than two hours under this influence, were such, that though the sleep was not interrupted, yet Valentin considered it necessary to admit air in order to save the animal. In another experiment, when the air was extenuated to 41 millimetre-i.e, to of the external pressure-a stream of blood rushed from the animal's nostrils, but by the admission of air of the usual density the animal recovered quickly. The

appearance of a greater quantity of moisture at the nostrils was a regular phenomenon produced by the more rapid extenuation of the surrounding air. Valentin particularly points out the difference in the effect of a rapid and gradual diminution of pressure, the latter being borne much better than the former. The same author has also frequently subjected sleeping marmots to increased pressure. When the air is pumped in slowly, the pressure could be increased to that of three atmospheres (2160 millimetres) without awaking the animals, or producing any striking symptoms; rapid pumping in of air caused the animals to awake for a short time; sudden emission of the condensed air had the same effect, and effected in all animals a profuse discharge of mucous fluid from the nostrils, and in one case hæmorrhage from the same parts. The record of the other contents of Valentin's valuable paper on the hybernation of marmots we must defer to the next Report.

Aberle measured with Vierordt's instrument, and under the superintendence of that physiologist, the diameter of the radial artery, on several persons, and at different periods of the day. He found that the diameter of the artery is larger in the afternoon (after dinner) than in the forenoon. The average diameter, in different persons, varied between 2.09 millimetres (short stature) and 3-18 millimetres (tall people); in the forenoon we find the figures, 1·74— 2.92 millimetres; in the afternoon, 2·45-3.44 millimetres.

Wagner recommended, as the best object for the observation of phenomena connected with the circulation, the mesenteric vessels of young cats or rabbits under the influence of ether, as offering a much more distinct view of the capillary circulation than other objects generally used. The author constantly saw in his examinations the following three different formative elements: a, red globules, principally in the more rapid central part of the stream; b, colourless granular globules, of much slower movement, in the peripheric part of the stream, where they sometimes considerably accumulate, through the diminished power of the heart; c, small, sometimes aggregated, strongly refractive globules, much like fat-granules. The observation relating to the colourless globules shows, that the estimation of their proportion in a drop of blood, abstracted from a certain part, may lead to erroneous conclusions, as their quantity may vary, in the same vessel at different times, with the variation of pressure, &c. The turgid chyliferous vessels of the mesentery exhibit only very small molecules, here and there larger fat-globules, and always a few red blood-discs, the progressive movement of which could be distinctly traced. This movement was not continuous, but periodic. The contraction of the villi and of the intestinal canal, and other movements of the animal, appeared to exercise influence on this motion; the acts of respiration did not seem to promote it. Sometimes, in the course of the observation, the chyliferous vessels became almost filled with blood globules, which the author is inclined to explain by the supposition of the rupture of small bloodvessels within the villi.

Kunde adopts Bichat's view regarding the three principal organs from which death may originate, substituting, however, the medulla oblongata for the brain. Apparent death may be artificially produced from every one of these organs. The author's experiments relate, however, principally to apparent death from the heart. The method adopted by him consists simply in compression of the atria of the heart between the fingers, which can easily be effected in young cats, dogs, rabbits, and in frogs, without any lesion of the thorax. If the heart of a young cat is compressed, the respiratory movements continue for a time, the diaphragm contracts, and the animal cries; soon the mucous membrane of the mouth and nose becomes blue, and then completely pale; after this, the respiratory movements cease, the pupils become dilated, the voluntary and reflex movements cease. If the compression is at this period discontinued no sounds of the heart are perceived; but soon the first sound reappears, and then the second, and the heart resumes its functions as usual.

After this, a respiratory movement is observed preceding all the other motions of the muscles of the trunk or limbs; later, the mucous membranes regain their colour; finally, the animal rises, moves first in an unsteady manner, but by degrees recovers completely. In the frog, the author witnessed the cessation of the reflex movements at first in the posterior extremities; the lymphhearts cease last; the animal appears without life; the capillaries contain only a small quantity of blood; the veins are gorged. Further experiments, performed on frogs under the influence of strychnia, show that the tetanic convulsions become suspended as soon as the heart is compressed, and reappear after the discontinuance of the compression. The author concludes from this fact, that paralysis of the nerves may be produced by a mere change in the tension of the vessels. He is further inclined to confirm Bichat's proposition, that an important influence is exercised on the brain by the motion incessantly imparted to it through the contractions of the heart. In favour of the latter inference, Kunde adduces Heidenhain's discovery, that a tetanic state of a nerve may be caused by a continuous repetition of mechanical concussion; and points to the constantly-repeated shocks applied to the nervous centres by the passage of the blood-globules through the capillaries.

In the course of these experiments, Kunde was enabled to confirm in many points Kussmaul's observation regarding the influence of compression of the blood vessels and the beart on the state of the iris. Contraction of the pupil was the first phenomenon, which was soon followed by rotatory movements of the bulb, anæmic state of the vessels of the iris, dilatation of the pupil, slight convulsions, and exophthalmus, with complete dilatation of the pupil. Suspension of the compression is followed only after fifteen to twenty seconds by gradual contraction of the pupil. Dilatation, however, was the only constant phenomenon, and this is the regular consequence of diminished pressure from the heart, whatever may be the cause of the latter.

III. DUCTLESS GLANDS.

1. KÖLLIKER: On the Function of the Spleen. (Loc. cit., sub. i.) 2. IASCHKOWITZ: Contribution to the Erperimental Pathology of the Spleen. (Virchow's Archiv, Band xi. p. 235, 1857.)

Kölliker's researches confirm the view, which is being more and more generally adopted, that the colourless blood-globules are formed in the spleen; and partly in that organ itself, partly in the liver, partly in the blood, are transformed into red globules.

Iaschkowitz studied the effect produced by section of the plexus lienalis on the structure of the spleen. Nine experiments performed on dogs, by section either of the whole plexus lienalis, or only of the superior or inferior half of it, show that this section causes in the corresponding part of the splenic tissue > an altered state-viz, congestion of blood, softening, tension of the capsule, effusion of coagulating blood in large quantity through incisions into the capsule. We see, therefore, that the result of these experiments is analogous to that of section of the sympathetic nerve of the neck; and the author draws the inference, that mere nervous disturbance, without pathological change in the composition of the blood, may cause an alteration of the tissue of the spleen. Further experiments must elucidate the influence exercised by such alterations of the spleen on the mixture of the blood.

The same author observed, during these experiments, contraction of the spleen in the direction of the longitudinal axis, as well under the influence of galvanic irritation as under that of the atmospheric air.

* Heidenhain: Physiologische Studien. Berlin, 1856.

IV. SECRETION; EXCRETION; METAMORPHOSIS OF MATTER.

1. BERNARD: On the Influence of Alcohol and Ether on the Secretion of the Intestinal Tract, the Pancreas, and Liver. (Gaz. de Paris, No. 19, 1856; and Schmidt's Jahrb., vol. xciii. p. 24, 1857.)

2. DORNBLUTH: Observations on the Mechanism of the Secretion of Urine. (Zeitsch. für Rat. Med., vol. viii. p. 174, 1856; and Schmidt's Jahrb., vol. xciii. p. 275, 1857.)

3. BEIGEL: Researches on the Quantity of Urine, Urea, &c. (Wien, 1856; and Schmidt's Jahrb., vol. xcii. p. 5, 1856.)

4. V. FRANQUE: Contribution to the Knowledge of the Excretion of Urine in Man. (Dissert. Inaugur., Würzburg, 1855.)

5. NEUBAUER: On the Decomposition of Uric Acid in the Animal_Body. (Annal. der Chem. und Pharm., vol. xcix. p. 206, 1856; and Schmidt's Jahrb., vol. xciv. p. 7, 1857.)

6. CLOETTA: On the Presence of Inosit, Uric Acid, &c., in the Animal Organism. (Annal. der Chem. et Pharm., vol. xcix. p. 289, 1856; and Schmidt's Jahrb., vol. xciv. p 9, 1857.)

7. DELORE: On the Formation of Sugar in the Liver. (Gaz. Méd. de Lyon, No. 2, 1856; and Canstatt's Jahrsber. der Physiologie, p. 160, 1857.)

8. CHAUVEAU: New Researches on the Question regarding the Formation of Sugar. (Compt. Rend., May, 1856; and Canstatt, 1. c. p. 162.)

9. HENSEN: On the Formation of Sugar in the Liver. (Verhandl. der Würzburger Gesellsch., vol. vii. p. 219, 1856.)

10. HENSEN: On the Formation of Sugar in the Liver. (Virchow's Archiv, vol. xi. p. 395, 1857.)

11. BERARD: On the Place of the Production of Sugar in the Organism. L'Union Médicale, tome xi. No. 61, 1857.)

Bernard injected between five and six cubic centimetres (ie., rather more than ths of a cubic inch) of alcohol, diluted with an equal quantity of water, into the stomach of a dog, and found a few minutes later, when the animal was killed, the stomach filled with fluid exhibiting the characters of gastric juice, and a considerable quantity of the secretions of the pancreas and the intestinal glands in the cavity of the digestive canal.

In order to learn the influence of alcohol on the glycogenic function of the liver, the author chose two dogs that were as much as possible in the same condition after having deprived them of food for an equal space of time, he killed one of them immediately, the other after repeated injections of alcohol into the stomach. The liver of the former contained only a small, that of the latter a large, quantity of that insoluble substance which is afterwards transformed into sugar. The action of ether was found similar to that of alcohol, only more powerful.

The results of Valentin's experiments-that the quantity of albumen passing over from a solution of that substance, through a membrane into water, according to the laws of endosmosis and exosmosis, is increased or decreased by the greater or smaller degree of pressure acting on the solution-leads Dornbluth to the inference, that the absence of albumen in the urine indicates a low pressure acting on the secreting vessels of the kidneys. The circumstances leading to albuminuria are such as cause retardation in the return of the venous blood; and, through this, increased pressure on the secreting vessels-as contraction of the renal veins, tumours of the liver pressing on the vena cava, valvular diseases of the heart, &c. The pressure of the blood in the Malpighian bodies, the author argues, cannot be great, as the diameter of the vasa efferentia bears to that of the collected capillaries the proportion of 10 to 18, which must be connected with diminution in celerity and pressure. The impediment caused by the return of the blood from the capillaries into the

vasa efferentia is rendered smaller by the acuteness of the angles under which the transit takes place, by the communication of the vasa efferentia with wide meshes of capillaries, as also by the diminution of the quantity of blood, in consequence of the abundant secretion in the Malpighian bodies. This reasoning is borne out by the result of Ludwig's experiments, showing the pressure in the renal veins to be equal to that in the jugular veins. The prominent points in the mechanism of the secretion are, according to the author's view, that in the Malpighian bodies, under a low pressure, a diluted transudation takes place, carrying with itself the easily diffusible substances that are not retained by combination with proteinaceous constituents; the amount of solids in the transudation depends on the diffusive faculty and the relative quantity of the substances present in the serum of the blood. In the urinary tubuli an endosmotic interchange takes place between the transudation of the Malpighian bodies and the blood circulating in the capillaries round the tubuli; one of the principal results of this interchange being a transition of water from the fluid in the tubuli into the blood. The quantity of urine depends principally on the process in the Malpighian bodies; the larger the amount secreted by these, the more accelerated will be the stream in the tubuli, the less the time for absorption of water by the blood.

Beigel gives the result of his observations on ten healthy male and six healthy female individuals; the age of the former was between twenty and thirty years, height 169 to 176 centimetres, weight 74 to 79 kilogrammes; age of women, nineteen to thirty years, height 165 to 170 centimetres, weight 63 to 67 kilogrammes; diet of both sexes, mixed. Beigel adds remarks on the influence of very liberal and low diet, of exercise, and of several medicinal agents. Of similar nature are Von Franque's observations made on his own person, being in the twenty-second year, 1738 centimetres high, weighing 62-64 kilogrammes. Both authors agree in corroborating the experience of other physiologists:-1st. That an increased ingestion of azotized food leads rapidly to increased egestion of urea through the urine. 2nd. That diminished ingestion of azotized food does not lead to a corresponding dimi nution in the excretion of urea; that continued abstinence from nitrogenous food is followed only after some time by a decrease of the normal quantity of the urea. 3rd. That the excretion of urea is much augmented by bodily

exercise.

Beigel's examinations lead him, in addition, to the assertion, that Bischoff's inference regarding the coincidence of a high specific gravity of the urine and a large proportion of urea, is correct with reference to healthy male individuals, but not equally so to women, whose urine was found to contain in the average less urea than that of men, in spite of the high specific gravity. Another proposition arrived at by Beigel, as the result of his experiments, is, that increased metamorphosis of matter need not be connected with increased temperature, nor diminished metamorphosis, through insufficient ingestion of food, with decreased temperature, provided the abstinence be not continued too long. Neubauer, after having ascertained the composition of the urine of rabbits living on their usual food, and especially the absence of uric acid, added between 2 and 3 grammes of uric acid to their daily allowance of victuals; the principal alteration thereby produced in the urine was an increase of urea from 13 grammes to 2, to 2.5, and even 42 grammes, which increase disappeared almost immediately when the uric acid was left off. Other experiments of a similar nature led to an analogous result. Neubauer infers from this, that uric acid is decomposed within the body into urea and carbonic acid. When a larger quantity of uric acid was given, a small portion of it was excreted as uric acid, and perhaps also in the shape of oxalic acid.

Cloetta's memoir forms a contribution to our knowledge of the metamorphosis of matter, and particularly with respect to the questions, whether