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recognised by Millon's reagent. Another portion of sweat was acidified with hydrochloric acid, shaken with ether, the ethereal extract evaporated to dryness, and the residue taken up with water; this solution showed the presence of aromatic oxy-acids by the red colour produced by Millon's reagent. Indoxylsulphuric acid was sought for by Jaffe's test, with negative results; the same test gave, however, a red colour, showing the presence of scatoxyl. It is suggested that the blue colour of the sweat in chromidrosis is due to bacteria. W. D. H.

Relation of Tyrosine to Hippuric Acid. By K. BAAS (Zeit. physiol. Chem., 11, 485-491).- Many aromatic compounds which occur in the urine have been shown to be decomposition products of tyrosine formed in the alimentary canal. The question as to whether hippuric acid is derived from tyrosine also, has been investigated by Salkowski, Schotten, and Baumann, but the results obtained have been somewhat contradictory. The present research was carried out in human beings, and consisted in comparing the normal urine with that secreted during the administration of tyrosine. The hippuric acid was estimated by Schmiedeberg and Bunge's method; and the amount of sulphates and ethereal hydrogen sulphates by Baumann's method. The experiments show that giving tyrosine did not alter the amount of hippuric acid in the urine, and therefore that the normal formation of that acid does not result from the tyrosine in the intestine. The conclusion is also drawn that tyrosine does not always undergo putrefactive decomposition in the alimentary canal, but that in spite of the presence of bacteria, it may be wholly absorbed as such. W. D. H.

Urinary Pigments. By L. v. UDRÁNSZKY (Zeit. physiol. Chem., 11, 537-560).—On looking over the literature of the subject of urinary pigments, which extends from the beginning of the present century, it is found that the following conclusions can be drawn from the work at present done on the subject:-(1.) By the action of oxidising agents, indigo-blue and other indigo compounds, for example, indirubin, can be obtained from normal urine. (2.) In most cases urobilin, which is identical with hydrobilirubin, is also present. (3.) In addition to the foregoing, pigments are obtained by boiling the urine with mineral acids, and are probably derived from the splitting up of certain chromogens in the urine by these strong reagents to one of these, the name uromelamin is given. It is to the investigation of this third class of pigments that the present research is mainly directed. A litre of normal urine was heated for a quarter of an hour with 5 per cent. hydrochloric acid, and extracted with amyl alcohol; on evaporating the alcoholic extract, a brownishblack, amorphous residue was obtained weighing 0-68 gram. This is the ordinarily received method of obtaining this pigment. experiment was repeated, using distilled water instead of urine, and a residue weighing 0:51 gram was obtained, having the same characters, including spectroscopic appearances. The prolonged action of hydrochloric acid in the cold has the same action on amyl alcohol. What this resinous substance is was not further investigated;

The

it was found, however, that the alcohol after distillation still possessed the same action on polarised light as previous to the separation of the pigment from it. This admixture of the resinous substance from the reagents used with the urinary pigment could not be prevented by attempting to wash the acid away from the alcohol by the use of water; it was not found possible to remove the acid in this way. By neutralising the mixture with chalk, however, the author considers he has been able to obviate this source of error. On account, however, of the unsatisfactory nature of amyl alcohol as a reagent, a method was sought for in which it was not necessary to employ it. The method ultimately adopted was as follows:-Normal urine was evaporated to about one-sixth of its original bulk at 60°; 10 per cent. hydrochloric acid was then added, and after 48 hours the crystals of uric acid thus formed were filtered off. The filtrate was boiled for 18 hours, at the end of which time the remains of the uric acid with an abundance of pigment were precipitated; the filtrate had an orange-red colour; to this, chalk and sodium phosphate were added; the bulky precipitate which was formed carried down with it the remains of pigment. The precipitate obtained from the urine by boiling was washed with cold water, hot water, alcohol, and ether, dissolved in dilute sodium hydroxide solution, and precipitated by sulphuric acid. This was repeated three times, and the final product was a bright, brownish-black substance, occurring in plates, but easily powdered. It was insoluble in cold water, dilute alcohol, ether, and chloroform, sparingly soluble in warm water, absolute alcohol, light petroleum, and concentrated sulphuric and hydrochloric acids. It was easily soluble in amyl alcohol, concentrated ammonia, but especially in solutions of potassium or sodium hydroxide. It can be heated to 115° without decomposition; with soda-lime it yields ammonia; on dry distillation, it gives a smell of formic acid, and after complete combustion leaves a minimal amount of ash which contains no iron. The average quantity in which it occurs in urine is 003 per cent. By the action of potash, it yields ammonia, formic acid, acetic acid, butyric acid, palmitic acid (?), catechol, protocatechuic acid, and the residue is free from nitrogen, and has the following percentage composition :-Carbon, 62-26; hydrogen, 39; and oxygen, 33.84. W. D. H.

Chemistry of Vegetable Physiology and Agriculture.

Nitrifying Microbes. By M. MILES (Bied. Centr., 1887, 514-515). -Miles confirms Warington's observation as to the length of time which elapses between the infection of the liquid and the commencement of the nitrifying process, and he finds that this period of quiescence may be cut short by introducing a minute quantity of another and earlier culture. When calcium carbonate was absent, the microbes increased rapidly, but nitrification seldom occurred, and microbes which had been cultivated for some generations in liquid not containing calcium

carbonate, caused nitrification in dilute urine to which calcium carbonate had been added. It appears that those microbes which increase rapidly without nitrification are of peculiar aërobic forms, but if they cause rapid nitrification, then they belong to the anaerobic class. Solutions were tested for nitrous acid, but it was seldom found; when found it was in those solutions which gave no reaction for nitric acid, and in which micrococci appeared together with the true nitrifying microbe.

E. W. P.

Culture of Anaërobic Bacteria. Morphology of Butyric Fermentation. By M. GRUBER (Chem. Centr., 1887, 535).-Gelatin, contained in a glass tube about 2 cm. wide, fused together at one end and drawn out to a neck 5 to 6 cm. long, and 3 to 4 cm. wide, is inoculated, the tube placed in water at 30-35°, exhausted and sealed. The fused gelatin is spread over the surface of the tube by rotation. In using this method, the author found that the three bacteria known by the joint name of Clostridium butyricum (Bac. amylobacter), are capable of producing butyric acid and butyl alcohol from carbohydrates. N. H. M.

Distribution of the Nitric Ferment and its Function in the Disintegration of Rocks. By A. MÜNTZ (Ann. Chim. Phys. [6], 11, 136-144). The bare surfaces of calcareous, felspathic, micaceous, schistose, and other rocks at the summits of mountains in the Pyrenees, Alps, and Vosges, yielded large numbers of the nitric ferment, which penetrates to a considerable depth in the cracks in the rocks, and is especially abundant on surfaces which show the greatest disintegration. This organism is not killed by the lowest temperatures of the Alps.

The rocks concerned, especially those above the limits of vegetation, contain small quantities of carbon, which make the rock blacken when heated. This carbon is derived from air and rain. The author has previously proved that alcohol vapour exists in small quantities in the atmosphere. Direct experiments show that the nitrifying organisms will exist and produce nitrates with no other sustenance than the mineral constituents of the rock on which they are placed and small quantities of alcohol vapour and ammonia suspended in a moist atmosphere. Some carbon is also found to have been deposited in or upon the rock on which the organisms are living. There is every reason to believe that these nitrifying organisms play an important part in the superficial disintegration of rocks even at the highest levels. C. H. B.

Methane Fermentation of Acetic Acid. By F. HOPPE-SEYLER (Zeit. physiol. Chem., 11, 561-568).—Calcium acetate was dissolved in water, and river mud added to the solution in a flask. The mixture was allowed to stand at the atmospheric temperature for seven months, during which time the gas which was evolved was collected over mercury and occasionally analysed. For the first few weeks, some atmospheric nitrogen was present in the mixed gases, but after this time carbonic anhydride and methane were alone present, in the

proportion 1 2 approximately. The residue in the flask consisted almost entirely of calcium carbonate. The decomposition which had occurred may be represented thus: (C2H2O2)2Ca + H2O = CO ̧Сa + CO2 + 2CH1. In addition to the calcium carbonate, there was also in the flask a small amount of sodium carbonate: this was derived from a slight impurity in the original salt used, together with some derived from the glass wall of the flask. There was also organic matter from the mud, and a large number of bacteria. The change is believed to be due to the agency of the bacteria, although to which special variety has not yet been ascertained. By an experiment similarly carried out with calcium lactate, carbonic anhydride and methane in the proportion of 1:2 were evolved, the residue being composed of calcium acetate. It is possible, therefore, that methane in the alimentary canal is not always derived from cellulose.

W. D. H. Formation of Starch in the Chlorophyll Granules. By G. BELLUCI (Chem. Centr., 1887, 572).-In order to determine whether the production of starch under the influence of sunlight, and the subsequent reconversion during night time, is to be regarded as a physiological or as a chemical change, the effect of the presence of various substances was tried. Chloroform, and to a slighter extent, ether vapour, destroy chlorophyll, and also prevent the transformation of starch formed during sunlight; carbonic anhydride also diminishes the function of the chlorophyll, but does not destroy it, if the action is not allowed to continue unintermittently for 24 hours. saccharification of starch proceeds in the dark, even in cut-off leaves, but more rapidly with free access of air. From these experiments, the author concludes that the phenomenon is a physiological and not a chemical change. V. H. V.

The

Crystalline Deposits in Dahlia Tubers. By H. LEITGEB (Ann. Agronom., 13, 378-379).-In order to exhibit the sphero-crystals of inulin, the common plan is to soak sections of dahlia tubers in alcohol. The author having allowed a tuber to soak for several years in this liquid, finds the spheres of inulin with radial striæ grouped in the peripheral region of the tuber. But besides these he has noticed spheres composed of an amorphous nucleus surrounded by an envelope formed of radiating needles. These crystals abounded in the pith and inner portions of the parenchyma. They leave after combustion a mineral residue of the same shape as the crystals, consisting of calcium phosphate. The amorphons nucleus consists of an organic substance which is neither inulin nor fatty matter.

J. M. H. M.

Absorption of Ammonia by Clay. By W. WIPPRECHT (Bied. Centr., 1887, 517-518).-The experiments were made on a clay from. Texas. All ammonia was removed from the clay previous to the experiments by heating at 400°. The following conclusions are drawn. Moist clay contains more ammonia than drier clay. If the moisture remains constant, the more ammonia is absorbed the longer the clay remains exposed to the air. Dried clay when moistened and exposed for one day to the air, absorbs a considerable quantity

of ammonia. When moist clay is exposed to air, the loss of water is accompanied with a proportionately greater loss of ammonia; on the other hand, when clay is absorbing water from the air, it at first gains more ammonia than it would lose during the evaporation of the same amount of water. A. J. G.

Analysis of Onions. By C. A. GOESSMANN (Pharm. J. Trans. [3], 18, 77-78).—1000 parts of air-dried onions, without the leaves, consisted of 892 parts of water, and 108 of dry matter, containing 2:12 parts of nitrogen, 0:48 part of sulphur, and yielding 4:36 parts of ash. The percentage composition of the ash was

KO. 38.51

Na O. CaO. MgO. Fe2O3.
1.90 8.20 3.65 0.58

SiO2. P2O5
3:33 15.80

The sulphuric acid in the ash was not determined, because the 0-48 part of sulphur in 1000 parts of the onion includes the total amount of sulphur present in any form. Whilst sulphur is an essential constituent of all plants, it is only in a comparatively few families that it exists in volatile combinations capable of imparting strong and offensive odours. As many plants of this kind when eaten by cows impart their odour to the milk, their absence is one condition of good dairy farm pastures. R. R.

Manurial Experiments with Various Phosphates. By KREMP (Bied. Centr., 1887, 525—527).-The crop was oats, and various phosphates-super, precipitated and basic cinder, were used in combination with Chili saltpetre. Very little or no gain was obtained by the addition of the phosphates. Analyses of the soil are not given.

E. W. P. Manuring with Various Phosphates. By W. ROBERTS (Bied. Centr., 1887, 528-530).-Superphosphate was compared with precipitated and Ardennes phosphates as to its action on the growth of wheat. The Ardennes produced an intermediate crop, whilst that from the use of the precipitated phosphate was only an eighth of the net gain by the use of superphosphate. Further experiments on potatoes, roots, and buckwheat showed a similar result, the reduced phosphate lagging far behind. E. W. P.

Analytical Chemistry.

Improved Form of Elliott's Gas Apparatus. By J. B. MACKINTOSH (Amer. Chem. J., 9, 294-296; compare Abstr., 1884, 215). The measuring tube is provided at the top with a three-way stopcock, and is thus permanently connected on the one side with the absorption burette, on the other with the explosion burette, the small funnel for the top of which is no longer required.

A convenient method of preparing oxygen for gas analysis is by the

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