40° C., for some hours, the latter constantly contained more casein than the former. In the present communication, he repeats and confirms his former experiments, and observes that the formation of the casein cannot be regarded as a process of coagulation; moreover, that a short exposure to 40° C. is not sufficient to effect the conversion, but that several hours are required. At the same time he finds a diminution of temperature of from 10° to 15° C. below the temperature of the body to render the process much less energetic. The last secreted milk shows the process best, whilst that which has long been retained in the gland shows it to the least extent. His experiment shows further that the process is not continuous but stays at a certain point. Other experiments made for the purpose of determining the formation of fat in milk and in cheese on exposure to the air, seemed to show that the occurrence of fat is to some extent connected with the presence of fungous spores in the milk, and that it proceeds from the splitting of albuminous compounds.

4. The variations which occur in the elimination of urea are an evidence of the greater or less activity of the oxidation of the nitrogenous substances, and, consequently, of the activity of the nutritive processes. The authors thought that the influence of electricity on nutrition might be determined by estimating its effects in causing variations in the amount of urea discharged. They experimented chiefly upon rabbits in consequence of the facility with which these animals can be catheterised, and occasionally they made themselves the subjects of experiment. As a general rule, the electrization lasted half an hour, one of the rheophores being placed upon the hind foot and the other in the lumbar region. The method of Lecomte was used for estimating the urea, consisting in estimating the nitrogen of the urea, treated with the alkaline hypochlorites (thirty-seven cubic centimetres of nitrogen corresponding to one decigramme of urea). The general results obtained were, that the passage of interrupted currents diminish the quantity of nitrogen; that continuous centrifugal currents constantly diminish the amount of urea and augment that of the urine; that continuous centripetal currents augment the production of urea without notably increasing the secretion of urine, which in some instances was even diminished. Further, they are disposed to believe that interrupted currents weaken the phenomena of general nutrition, and that continuous currents by facilitating endosmose and dialysis, increase the activity of the changes occurring in the tissues, and, in addition, that the centripetal current when acting on the central nervous system, causes stronger reaction, a kind of artificial febrile state which explains its effects.

HEART.-RESPIRATION.-ANIMAL HEAT.

1. A. BAYER: Clinical Evidence that the first Sound of the Heart is due to Muscular Contraction. (Archiv f. Heilkunde, Band x, p. 270.)

P. GUTTMANN: On the cause of the first Sound of the Heart. (Virchow's Archiv, Band xlvi, p. 223.)

P. NIEMEYER: On the cause of the first Sound of the Heart. (Deutsche Klinik, 1869, Nos. 15 and 16. Also Centralblatt, 1869, No. 23.) 2. SCHEREMETJEWSKI: On the changes in the Chemistry of Respiratory Process effected by the addition of Combustible Molecules to the Circulatory Blood. (Centralblatt, 1869, p. 691; and Sächs Akad. Sitzungsb. 1869, p. 154-194.)

3. SIEGMUND FLEISCHER: On the Influence of Hydrocyanic Acid and Woorara on the Temperature of Mammals. (Pflüger's Archiv, Band ii, p. 432.)

1. The mode of origin of the first sound of the heart, and whether it originates in the vibration occasioned by the sudden tension of the auriculo-ventricular valves, or is a muscular sound caused by the contraction of the thick muscular walls of the ventricle is a question that has once more been raised. M. Bayer adduces a case in support of his opinion that the first sound of the heart is muscular, in which during life a systolic sound was heard, whilst a post-mortem examination revealed insufficiency of the mitral and bicuspid valves, together with stenosis of the venous orifices. In this case, he is of opinion that the valves were physically incompetent to produce the sound. M. Fräntzel in commenting upon this case, however, observes that the proof here adduced is not very satisfactory, as every one has met with cases of incompetence of the arterial valves, yet in which a diastolic sound was audible. The question, in fact, resolves itself into one of degree. 2. M. Guttmann is opposed to the idea of the first sound being a muscular sound, on the ground that in dogs from which the blood had been drained, the sound was very different from that of healthy dogs, and his comparative experiments have led him to the conviction that the first sound is essentially valvular, the muscular contraction only slightly participating in its production. It must be admitted that, however freely dogs are bled, sufficient blood must still remain to render the valves tense, whilst, at the same time, by the papillary muscles contracting, the valves are rendered tense. 3. M. Niemeyer, without adducing any fresh evidence in favour of his opinion, simply holds that the systolic sound has a muscular and not a valvular origin.

4. M. Scheremetjewski made his experiments in Ludwig's laboratory, and employed the apparatus constructed by Sanders-Ezn, and described in the Centralblatt,' for 1867, with some slight alteration. He prefixes to his remarks the results of his experiments on the exchange of nitrogen gas in respiration, and in reference to this point states that in eighty-two observations the amount of nitrogen only remained unaltered in seven. Yet in the greater number of the experiments, the difference was so small that it might be attributable to error in the estimates, and in some of them there was slight increase, in others slight decrease of the amount. In twenty cases, on the other hand, the amount of nitrogen was so materially diminished, and in eight so much increased, that it could not be fairly conceived to be due to gasometric errors. And though other sources of error were

possibly present, it was more probable that the alteration was effected during the respiratory acts. The frequency of the respiratory movements in animals were observed to vary to the greatest degree when the animals were first placed in the apparatus, but this was found both by M. Scheremetjewski and by Sanders-Ezn to exercise little influence on the exchange of gases. M. Scheremetjewski now compared the differences in the chemistry of respiration before and after the injection of oxidizable matters into the blood, and the first substance injected was lactate of soda, of which quantities containing from 0.3 to 0.8 grammes of lactic acid dissolved in from 2 to 2.5 centigrammes of water was first thrown in. The effects observed were that both the absorption of oxygen and the elimination of carbonic acid were increased to a considerable extent except in two cases in which the excretion of CO, was diminished, though in one of these, after the lapse of some time, an increase occurred, and in the other the decrease was very small. The mean of all the experiments showed that both the absorption of O and the excretion of CO, had augmented 1.25 fold, the two exactly counterbalancing each other. The increase of the gas-exchange was proportionate to the amount of the lactates injected, and was maintained for an hour, but never rose to so great an extent that it could not be explained by the combination of the lactic acid injected. That this really occurred seemed to be shown by the rapidity with which an exaltation of the products of its combustion made their appearance, by their quantity bearing a direct proportion to the amount of the lactate injected, and by experiments showing that even when very large quantities were introduced, they rarely appeared in the urine. Now the increase in the quantity of CO2 exhaled might be dependent on some other augmentation of the respiratory process occasioned by the substance injected. In order to exclude this possibility, M. Scheremetjewski compared the gas-exchange of pure blood with blood containing lactates during its passage through the kidneys in dogs. Here also an increase was observable, whilst simple addition of the lactates to the blood caused no notable alteration. Scarcely any other explanation, therefore, is admissible than that the phenomena observable are dependent on combustion of the lactates. Grape sugar was found to behave itself very differently from the lactates, occasioning no alteration in the gas-exchange, which stands in opposition to the very generally received opinion that sugar undergoes rapid combustion in the body. An increase of gas-exchange analogous to that occurring with the lactate of soda, was observed with carbonate of soda and glycerine, but no remarkable alteration took place with formiate, acetate, or benzoate of soda.

5. Fleischer states that from his experiments hydrocyanic acid cannot be regarded, as Hoppe-Seyler maintains it to be, an antiphlogistic remedy, since a decided diminution of the body temperature only occurs when such an amount has been subcutaneously injected as to produce collapse. With smaller amounts it either remained unaltered or slightly increased. In regard to woorara, he found that

this subcutaneously injected caused a very transitory elevation of temperature, both in fatal and in non-fatal doses. In nearly fatal cases this elevation was followed by marked diminution of temperature, which was persistent..

1. G. SVIERCZEWSKI and Prof. W. TOMSA: On the Physiology of the Nucleus and Nucleolus of the Nerve Cells of the Sympathetic. (Centralblatt, No. 41, 1869.)

P. 1.

2. J. GERLACH: On the Decussation of the Centric Extremities of the Hypoglossal Nerves. (Henle and Meissner's Zeits., 1869, 3. On the Nerves of the Peritoneum. By E. CYON, Ludwig's Arbeilin aus der Physiolog. Arstatt zu Leipzig, 1869.

1. THE following observations on the physiology of the ganglioncells of the sympathetic nerve have been made in the physiological laboratory at Kiew:

a. In regard to the movements of the nucleolus. If isolated nervecells from the sympathetic ganglia of the frog are examined in the serum of the blood of the same animal in lymph, or in the aqueous humour, and the nucleolus be carefully examined with an ocular No. 3 and No. 8 Hartnack's objective (immersion lens), we may easily convince ourselves in a great number of cases that it changes its position in the interior of the nucleus, and this is especially visible when two nucleoli are present. The movement is usually, however, so slow that it requires great and prolonged attention to observe it; on the other hand, it is sometimes so active that it is impossible to sketch it on paper. Rapid movements occur in hungry frogs more frequently in winter than in summer. Admixture of water with serum accelerates the movements. The movement resembles ordinary molecular movement, being dancing or vibratile, and limited to the extent of a quadrant of the cell. The duration of the movements is various, in many instances it ceases within a quarter of an hour after the isolation of the nerve cell; whilst in other cases, providing evaporation be prevented, it will last twenty-four hours. The dependency of the movements of the nucleolus may generally be referred to chemical changes taking place in the nucleolus and the nucleus. Occasionally no movements can be observed.

b. Action of gases. The nucleus of nerve-cells, when these have been rapidly isolated and examined in fresh serum of frogs' blood appears as a clear vesicle, which includes one, two, or more, rarely three, nucleoli, and usually a few dark moving points. In a few cases the nucleus is filled with an extremely fine granular precipitate. The nucleoli, when thus examined, have a polyhedral form, and a dull aspect. Very careful observation often shows the presence of one or several dark granules in the nucleoli.

Exposure to the action of oxygen or hydrogen in Stricker's gas chamber causes the following changes:-The nucleus becomes clearer,

two kinds of matter can be differentiated in the interior of the nucleoli, dark granules and a clear mass through which these granules are scattered. The number of granules in the nucleoli varies from two to six, but if the nucleus contains two nucleoli each of them may only contain one granule. The author is convinced that the clear substance of the nucleolus exhibits changes of form under the influence of oxygen, becoming contracted, though he acknowledges that such alterations of form, on account of the minuteness of the object, are most difficult to observe. If carbonic acid be made to act on the cell different phenomena are observed-an insignificant quantity of a punctiform precipitate occurs in the nucleus, causing it to assume a darker appearance. The nucleoli become darker, especially at the periphery, and their contour changes from a polyhedral form to a more rounded one. The granules within the nucleolus become gradually invisible, causing its periphery to present a finely granular appearance. The movements of the nucleolus are usually increased.

c. Action of distilled water. This causes enlargement and increase of transparency in the nucleus. The nucleolus exhibits its composition very clearly, that, namely, of scattered dark granules in a clear substance. But, whilst the clear substance rolls itself up into balls, the contour of the nucleolus differs considerably from that which it originally possessed, and the dark granules retreat towards its periphery. The movements of the nucleolus sometimes increase, sometimes remain as before. If CO2 be transmitted through the fluid an abundant granular precipitate occurs in the nucleus, which is not again dissolved by O or H.

d. Phenomena accompanying desiccation. If oxygen or hydrogen gases, or air, be allowed to play over the preparation the contour of the clear substance of the nucleolus becomes more and more indistinct, and at length vanishes entirely, only a few dark granules remain, which are distinguished from any others present in the nucleus by their near approximation to one another. The addition of water causes the gradual reappearance of the clear substance of the nucleolus. If a current of CO2 be conducted through the gas chamber at a certain stage of inspiration, the nucleus becomes irregular in form with dentated edges, and the nucleolus entirely disappears. . . . On the addition of water the nucleus resumes its original form and the nucleolus reappears, whilst a granular precipitate occurs in the

nucleus.

c. Formation of nucleoli in the nucleus. When the nervecells are very rapidly isolated the contents of the nucleus are often quite transparent without granules, or with only a few performing more or less active movements. In a short time however a development of moving granules occurs which gradually increase in size, but diminish correspondingly in number.

In the first instance each granule enlarges independently, but subsequently the enlargement appears to result from fusion, and these processes may be accelerated by the addition of water or serum. In one instance in which a nerve-cell was contained in a mixture of one part of serum, one part of lymph, and two parts of water, the