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has not yet been investigated. The present research is concerned with this question in relation to the spleen and lymphatic glands of the ox. Lactate of zinc was obtained by Hoppe-Seyler's method, with the modification that the finely chopped organ was extracted by 0.5 per cent. sulphuric acid instead of by cold water; in this way, more lactic acid is obtained. By estimation of the water of crystallisation of the zinc salt, and of the hydrogen and carbon, the conclusion is drawn that both in the spleen and lymphatic glands it is sarcolactic acid which is present. W. D. H.

Pigments of Melanotic Sarcomata. By K. A. H. MÖRNER (Zeit. physiol. Chem., 11, 66—140).-The name melanin has been hitherto used for the pigments occurring in the eye, hair, and skin, in pathological new growths, and also for the decomposition products of chromogens in urine. The black pigment of the retina has been investigated by Berzelius, who found it contained a small quantity of iron, by Scherer who found no iron, and also by Rosow and Sieber. The percentage composition obtained by the various observers shows great discrepancies, and this, with their methods of preparing the pigment, renders it probable that they were not dealing with a pure substance. Concerning the black pigment of the skin of negroes and of the hair, still less is known, and although some few percentage estimations have been made by Sieber, the result cannot be described as a convincing one.

The pigment of melanotic tumours was first investigated by Heintz, who found that it was soluble in alkalis with difficulty, and that it contained no iron. An elementary analysis gave the following figures: C = 53·40, H = 4·02, and N = 7.10 per cent. Dressler made a similar investigation, and found in the pigment a small quantity of iron. Berdez and Nencki named the pigment Phymatorusin; they found it to be insoluble in water, alcohol, and ether, easily soluble in solutions of fixed alkalis or their carbonates, and in ammonia; from such solutions it was precipitable by acids, but was somewhat soluble in excess. The preparation contained carbon, hydrogen, oxygen, and nitrogen, sulphur in large amount (1067 per cent.), but no iron, phosphorus, or chlorine. In horses, they found in melanotic tumours a pigment with somewhat different properties, which they called hippomelanin.

In the urine of some of these patients, a pigment has been found which according to some is an excess of the ordinary urine pigments, and according to others is the same pigment that occurs in the tumour. It is turned a dark-brown colour by the action of nitric acid; and in some cases a similar change occurs after mere exposure. The uncertain and contradictory statements of previous observers cannot but render uncertain which of the above statements is correct. Again, in other cases of these tumours, particles of a brown pigment are found in the blood, the corpuscles having the normal shape and colour; similar granules have been occasionally described in the urine and urinary passages.

The present research was undertaken with the material supplied by a patient, the full particulars of whose case are given. During life, the urine showed the peculiar coloration above-mentioned; after

death, the tumour itself was investigated. Its situation was the shoulder; secondary growths were present in the liver, but none in the kidney substance. The blood, except for a low percentage of hæmoglobin, was normal. The colouring matter did not give any absorption-bands, but produced a general dimming of the spectrum, especially towards the violet end. The methods by which the pigment was investigated were: first, by the spectrophotometer to determine the extinction coefficients in different parts of the spectrum; and, secondly, by elementary analysis. Although the quantity of material at hand was small, and therefore some results are incomplete, and others put forward with reserve, yet certain definite conclusions were arrived at. The pigment was found to contain iron, which also was estimated spectrophotometrically, as well as by the usual methods; the spectrophotometric method consisted in converting the iron of the ash into ferric thiocyanate, and comparing its extinction coefficients with those obtained from a solution of ferric chloride of known strength similarly treated. Iron was present in small quantities; the failure of some previous observers to obtain the proof of its presence is accounted for by their having used hydrochloric acid in the preparation of the. pigment. It is found that this acid dissolves out nine-tenths of the iron from the pigment.

Baryta-water causes a precipitate in the urine, and this carries down with it a good deal of the pigment; this is filtered off. In the filtrate, the remaining portions of the pigment are carried down with the precipitate caused by lead acetate. For the method adopted for separating the pigment from the tissues of the tumour, the original paper must be consulted. The pigment obtained from these three sources is a brownish, amorphous powder when dry. It is partly soluble in acetic acid, and partly insoluble.

The following table represents the percentage composition, and the relative absorption for the region wave-length 562, for these different preparations:

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two are produced from a mother-substance by the action of the acid. They differ from one another in percentage composition, and in absorptive power. They resemble one another in solubilities, except with regard to acetic acid, and in colour to the naked eye. The high percentage of sulphur in the pigment insoluble in acetic acid agrees with the similar condition in phymatorusin. An important point brought out is the identity of the tumour pigment with that in the urine; it is probably brought to the urine by the blood, in which feebly alkaline liquid it is slightly soluble. It is not the same pigment as occurs in normal urine; that gives quite a different spectrophotometric chart. W. D. H.

Cobra Poison. By C. J. H. WARDEN (Chem. News, 54, 197-199; 209-211). Two samples of air-dried snake-venom contained respectively 16-26 and 15 43 per cent. of water. Fresh venom yields 25-50 per cent. of solid residue. For the author's experiments, the solution of the dried venom in distilled water was injected under the skin of the back of white or piebald China mice. A dose of 0·012 gram of anhydrous venom was fatal in four minutes, and the rapidity of action decreases as the quantity of poison administered is diminished; with 0-000016 gram, the animal may live three hours, whilst 0.000008 gram is not fatal. Very large and very small doses cause convulsions, intermediate doses do not. In the case of white mice, the fatal ratio of poison to body weight appears to be about 1: 10,000,000. Heating the solution of the venom soon produces marked coagulation, but it is only after heating for some time that the toxic activity is reduced, hence prolonged heating at a moderate temperature is more effective for such a purpose than short periods at higher temperatures. Similar remarks apply to the action of picric acid, which causes an abundant precipitate in solutions of the poison, and in some experiments a marked reduction in the toxic action when the filtered solution was employed. D. A. L.

Urine of the Tortoise. By T. W. MILLS (J. Physiol., 7, 453— 457).-The urine of the tortoise is liquid, ranging in colour from colourless to light amber, and is of an acid reaction. In some cases, it is green from admixture with bile in the cloaca. Albumin is invariably present; although probably this is derived from the intestine, via the cloaca. On allowing the urine to stand, the albumin having been removed, a deposit of uric acid crystals, of an orange colour occurs. On many occasions uric acid crystals were found in the urine without any treatment; these were always colourless. By Heintz's hydrochloric acid method, the amount of uric acid in the urine was estimated, and found to be several times greater than in human urine. Urea is altogether absent. The inorganic constituents do not differ in kind from those found in the urine of man.

W. D. H.

Chemistry of Vegetable Physiology and Agriculture.

Reduction of Copper Sulphate during Alcoholic Fermentation. By H. QUANTIN (Compt. rend., 103, 888-889).-In experiments on a small scale, it is found that copper existing in the form of copper sulphate to the extent of 0.05 gram per litre, is completely precipitated in the form of copper sulphide during alcoholic fermentation. On a large scale, doubtless a still larger quantity would be removed, but the quantity given is greater than would ever be introduced into the wort as a result of the use of copper sulphate as a remedy for mildew. Since moist copper sulphide is readily oxidised, it is important to avoid any aëration of the lees containing it. The sulphide is the only salt of copper which is insoluble in the must of grapes. C. H. B.

By U.

Alcoholic Fermentation of Dextrin and Starch. GAYON and E. DUBOURG (Compt. rend., 103, 885-887).—The authors have met with a species of Mucor which has the power of converting dextrin and starch into sugar, and then fermenting the sugar but, like Mucor circinelloides, it has not the power of inverting cane-sugar, and transforming it into alcohol. Other non-inversive ferments, on the other hand, have not the power of fermenting dextrin and starch. In beer wort or solutions of glucose, this mucor develops rapidly in large, spherical, ferment cellules. In dextrin or starch, it at first forms mycelial tubes, which soon swell up, divide, and form themselves into globular masses. In yeast-water containing sugar, the mucor forms only a bulky, unicellular mycelium.

The fermentation of dextrin takes place somewhat slowly, and that of starch requires still longer. The dextrin existing in beer is readily saccharified by this mucor and converted into alcohol, if the alcohol already in the beer is expelled before adding the ferment.

Eurotium oryzae, used in the manufacture of "koji," secretes a diastase which converts rice into a true malt, and this plant also inverts cane-sugar, but it cannot carry fermentation any further.

C. H. B.

Method of Preventing Secondary Fermentations. By U. GAYON and G. DUPETIT (Compt. rend., 103, 883-885).—The addition of tannin in quantities of 0.5-10 gram per litre gives good results, but does not prevent the development of Mycoderma aceti.

Salts of bismuth, even in small quantities, completely prevent secondary fermentations. The addition of 0.1 gram of basic bismuth nitrate per litre almost entirely prevents any increase in the acidity of the wort, and by keeping the yeast pure produces a distinct increase in the proportion of alcohol. The character of the results is seen from the following table. The first column in each set of experiments shows the behaviour of the wort containing the bismuth salt, and the second column shows the behaviour of the ordinary wort:

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Is Free Nitrogen formed during Putrefaction ? By A. EHRENBERG (Zeit. physiol. Chem., 11, 145-179).-Considering the important part that nitrogen plays in the organisms of plants and animals, many researches have been undertaken to determine, first, whether the atmospheric nitrogen takes any part in the nutrition of organisms, especially low organisms like bacteria, or whether as a result of decomposition, nitrogen in the free state is formed; the conclusions drawn by various workers are most contradictory. The present research is devoted only to the investigation of the question as to whether nitrogen is formed in putrefactive processes. The author intends to pursue the subject further in relation to nitrification. By means of an apparatus, which is described and figured, the use of caoutchouc stoppers is dispensed with, as diffusion takes place through these; wherever a stopcock is necessary, it is immersed in a trough of mercury. The gases formed by various putrefying mixtures were analysed. The method of gas analysis is preferable to that of nitrogen estimations, since certain nitrogenous compounds, formed by putrefaction (e.g., of the quinoline and pyridine groups), undergo dissociation at a high temperature. The substances investigated were dried blood moistened with cow's urine, cow's urine alone or mixed with calcium carbonate, and the dung of horses and COWS. These substances were mixed with some liquid in which putrefaction was taking place, and the investigation carried out in the presence of pure oxygen, so that only the aërobic organisms could act; carbonic anhydride was formed, but no nitrogen. In other experiments carried out in the absence of oxygen on a mixture of broth, sugar, peptone, sodium phosphate, sodium chloride, and sodium nitrate, it was also found that no nitrogen was formed. These experiments were carried out in an atmosphere of carbonic anhydride, in which only the anaerobic bacteria would be able to act. It was also found that during the slow combustion of organic materials no nitrogen was formed. W. D. H.

Absorption of Carbonic Anhydride by Leaves. By P. P. DEHÉRAIN and MAQUENNE (Ann. Agronom., 12, 526–534).—-The authors cite determinations which confirm the conclusions already arrived at by them, namely, that the absorption of carbonic anhydride

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