140 ABSTRACTS OF CHEMICAL PAPERS BACTERIOLOGICAL, PHYSIOLOGICAL, ETC. Estimation of Dextrose in Urine and Blood. B. Oppler. (Zeitsch. physiol. Chem., 1911, 75, 71-134 ; through Chem. Zentralbl., 1912, I., 380-381.)-For the estimation of dextrose at concentrations below the limits at which the qualitative tests are sensitive, the urine is decolorised by the addition of crystallised phospho- tungstic acid, protected from the light. After standing for twelve hours, the liquid is filtered, and the filtrate treated with neutral lead acetate ; after a further twelve hours in the dark it is again filtered, and the lead is removed by hydrogen sulphide. Urines thus treated in most cases no longer contain any perceptible quantity of laevo-rotatory substances ; at the same time, substances which interfere with the cupric reducing reaction are removed.The dextrose can then be estimated by polarisation, or cupric reduction, before and after fermentation by yeast. Healthy urine contains, however, cupric reducing, optically inactive substances, which are removable by yeast, to an amount equivalent to 0.04 per cent. of dextrose. In the urine ofBACTERIOLOGICAL, PHYSIOLOGICAL, ETC. 141 mental patients dextrose was found in the majority of cases, but mostly in small amounts. Such urine frequently shows an abnormally high Imo-rotation, equivalent to as much as 0.97 per cent. of glucose. The application of the above method of purification to blood showed t hst the colouring, Imo-rotatory, and interfering matters of the serum behaved very much in the same way as those present in urine, and the methods applicable for the estimation of sugar in urine are likewise suitable in the case of blood.J. F. B. Estimation of Sugar in Blood. D. Takahashi. (Biochem. Zeitsch., 1911, 37, 30-33.)-Results of estimations of sugar in dogs’ blood by various methods are recorded ; the methods described by Bertrand and by Kumagawa and Suto yielded results which agreed with one another and with those obtained by the polarimetric method. The total amount of sugar found to be present varied from 0.12 to 0.18 per cent. when these methods were employed, whilst Bang’s method gave results which were about 0.03 per cent. higher. No sugar was found after fermentation. w. P. s. Are the Alkalinity and Peroxydase of Milk Identical? W.D. Kooper. (Zeitsch. Untersuclz. Nahr. Geizussm. , 1912, 23, l-l3.)-The alkalinity value of milk (as measured by the quantity of acid required to change the violet coloration to green when 100 C.C. of milk are treated with a mixture containing p-phenylenediamine hydrochloride, guaiacum , and hydrogen peroxide, the alkalinity value being expressed in C.C. of Tc acid) is not a constant quantity, varying from 106 to 112, with an average of 110. The value is higher for colostrum, but decreases as the lactation period proceeds ; for fresh goats’ milk it generally lies above 120. The addition of water to milk raises the value, whilst the acidity of the milk is diminished, and the decrease in the acidity is greater in the case of old milk than with fresh milk; on the contrary, the increase in the alkalinity is smaller.These and other results of an investigation carried out by the author led him to the opinion that the property possessed by milk of being capable of producing a coloration with the above-mentioned reagent is due to the action of inorganic compounds contained in the milk. These compounds appear to be various phosphates of the alkalis and alkali-earths. w. P. s. Separation of Rennin and Pepsin by Means of the Electric Current. W. E. Burge. (Amer. J. Physiol., 1912, 29, 330-334; through Chcm. Zerztralbl., 1912, I., 697.)-When an electric current of 10 milliamp4res was passed through a solution containing rennin and pepsin for twenty-four hours, the liquid completely lost its property of digesting fibrin, whereas the activity of the rennin, as displayed by its power of coagulating fresh milk, remained unchanged.J. F. B. Estimation of the Acidity of Urine. L. Grimbert and J. Morel. (Comptes rend., 1912, 154, 378-380.)-1n titrating the acidity of urine, with phenolphthalein as indicator, apparent neutrality is obtained when the monosodium phosphate has been converted into disodium phosphate, but the absolute acidity would correspond to the formation of trisodium phosphate. If the conversion of the monosodium salt into142 ABSTRACTS 0 F CH EMICA L PAPERS the disodium salt be regarded as indicating the real acidity, account must still be taken of the influence of ammonium and calcium salts upon the results of the titration. The first source of error may be obviated by titrating the ammonia by RonchBse’s formaldehyde method, and making a correction from the result obtained; and the second by adding to the urine a small quantity of powdered potassium oxalate to remove the calcium salts.If, then, the proportion of phosphoric acid in the urine ( =’@) be calculated into that of the Lorresponding monosodium salt, the acidity of the latter towards phenolphthalein will represent the phosphatic acidity, p , of the urine. On the other hand, if R represent the real acidity as estimated by direct titration, it is possible to calculate : (1) the organic acidity, a ; (2) the absolute acidity, A , and the amounts of monosodium and disodium phosphate in the urine. If the phosphatic acidity is inferior to the real acidity, disodium phosphate cannot be present, but there will be organic acidity. Since a=R - p , and A=2p+a, the pro- portion of monosodium phosphate will be equivalent to pxa-680. Again, if the phosphatic acidity is superior to the real acidity, there can be no organic acidity, but the total phosphatic acidity must be distributed between the acidity due to the mono- sodium phosphate (=m), and that due to the disodium phosphate, d. The calcula- tions would then be as follows : m= R, d = p - R, A = 2B+ d, whence- NaH,PO,= R x 3.680, and Na,HPO, = d x 4.356. C. A. M.