1917] AGRICULTURAL CHEMISTRY AGROTECHNY. 207 



chicken, duck, turkey, goose, human, and placental blood, and a number of 

 pathological specimens of human blood, and in the whole blood, plasma, and 

 corpuscles of the calf, goose, chicken, and ox, are submitted, together with a 

 detailed procedure for the determination of amino acids In blood. See also a 

 previous note (E. S. R., 37, p. 14). 



A rapid method for detenniaing calcium in blood and milk, H. Lyman 

 {Jour. Biol. Chein., 29 (1911), No. 2, pp. i69-i78).— Applying the principles 

 previously used for determining calcium in urine and feces (E. S. R., 34, p. 508), 

 a slightly modified procedure is described for determining calcium in blood and 

 milk. The method is simple and rapid and yields results accurate to within less 

 than 1 per cent. 



For the preparation of the calcium soap a reagent prepared as follows was 

 used : Four gm. of stearic acid and 0.5 gm. of oleic acid are dissolved in 400 cc. 

 of hot alcoliol, 20 gm. of ammonium carbonate dissolved in 100 cc. of hot water 

 is added, and the mixture is allowed to boil for a few moments. It is cooled 

 and 400 cc. of alcohol, 100 cc. of water, and 2 cc. of ammonium hydroxid (spe- 

 cific gravity 0.9) are added, and then filtered. This solution should be per- 

 fectly clear and if well stoppered will keep indefinitely. Before using, this 

 solution should be tested in the nephelometer for impurities. Since the intro- 

 duction of 0.002 mg. of calcium in the course of the determination would result 

 in an error of 1 per cent the importance of having reagents absolutely free from 

 calcium is emphasized. 



[Note on the Duclaux method] (Dept. Landb., Nijv. en Handel [Nether- 

 lands], Vcrslag. en Mcded. Dir. Landb., No. 5 {1916), p. 12). — The importance 

 of maintaining at 110 cc. the volume of the mixture being distilled after the 

 removal of the 10 cc. fractions, especially where a mixture of several acids 

 is being distilled, is pointed out. 



The detection of small amounts of oxalic acid in wine, A. A. Besson 

 {Schweis. Apoth. Ztg., 55 {1911), No. 7, pp. 81-85).— The author has thor- 

 oughly studied the method of Kreis and Baragiola,^ which consists of treating 

 50 cc. of the sample in the cold with 2.5 cc. of a 5 per cent calcium chlorid 

 solution, 2.5 cc. acetic acid, and 5 cc. of a cold saturated solution of sodium 

 acetate, allowing it to stand for 24 hours, and then centrifugalizing and ex- 

 amining the residue obtained. It is indicated that 0.01 per cent of oxalic acid 

 can easily be detected by this procedure. 



The results of the study show that the concentration of the reagents has a 

 great influence not only on the crystal form of the precipitated oxalate but 

 also on the delicacy of the test. A reagent consisting of a solution of 20 gra. 

 of pure crystallized calcium chlorid in 250 cc. water to which 250 cc. of acetic 

 acid and 500 cc. of a cold saturated solution of sodium acetate are added has 

 been found to yield excellent results. Ten cc. of this reagent is used for a 

 50 cc. sample of the wine. 



In the course of the study it was observed that in the samples containing 

 oxalic acid, even in amounts as small as 0.01 per cent, there was no growth of 

 mold, indicating the preservative action of the acid, at least in respect to molds. 

 Certain samples which originally gave positive tests for oxalic acid yielded 

 negative tests after several weeks. The oxalic acid thus appears to be de- 

 stroyed in time. No explanation is given for this phenomenon. 



Besearches on the ultrafiltration of milk, A. Bokkino {Arch. Ital. Biol., 64 

 {1915), No. S, pp. 417-425). — After having experienced some difficulty in the 

 ultrafiltration of milk through collodion membranes the author obtained a clear 



^SchwelB. Apoth. Ztg., 53 (1915), No. 29, pp. 397-400. 

 4066°— No. 3—17 2 



