AGEICULTURAL CHEMISTRY AGROTECHNY. • 713 



Some further contributions in regard to the examination and judgment 

 of milk, II. LiJHRiG and L. Kressner (Molk. Zig. \Hihleshe.im\, 25 (1911), No. 

 29, pp. 523-626). — Continuing previous woric (E. S. II., 25, p. 207), the authors 

 point out that hydrogen peroxid does not influence the refraction of a calcium 

 chlorid milk serum, except that which follows the dilution by ordinary water 

 and providing that the addition of this substance remains within certain limits 

 (3 per cent H0O2). Lactic acid was found to alter the refraction of the serum 

 in direct proportion to the amount added. 



The authors were not able to agree with Mai and Rothenfusser, however, in 

 regard to the undesirability of using spontaneously coagulated serums for deter- 

 mining the refraction. From some additional tests in regard to the relation of 

 the specific gravity to the refraction of the spontaneous milk serum, they 

 believe that just as good results can be obtained with such a serum as with 

 the calcium chlorid serum. 



The original acidity of milk, F. Bordas and F. Touplain (Compt. Rend. 

 Acad. 8ci. [Paris], 152 (1911), No. 19, pp. 127Jf-1276; abs. in Chem. Zentbl., 

 1911, II, No. 1, p. U; Ann. Falsif., 4 {1911), No. 32, pp. 297-301).— Milk reacts 

 alkaline with helianthin and lacmoid, while with phenolphthalein it reacts acid 

 and with litmus amphoteric. The authors believe that the apparent acidity 

 shown toward phenolphthalein is due to free casein. Milk, according to this, 

 originally contains no free acid (lactic or citric) nor an acid salt. When fer- 

 mentation of lactose sets in the acidity increases as a result of the separation 

 of free casein from the calcium caseinate with the formation or monocalcinm 

 phosphate from the preexisting dicalcium phosphate. Lactic acid is only de- 

 tectable with helianthin when the reactions with the respective salts have taken 

 place. 



Determination of phosphorus in milk, C. Sloniewski {Bui. Soc. Chim. 

 BcJff., 25 {1911), No. G, pp. 225, 226; abs. in Jour. Soc. Chem. Indus., 30 {1911), 

 No. 1//, p. 917). — As a result of determining the phosphoric acid in numerous 

 samples of milk, the author finds that no appreciable loss of phosphoric acid 

 takes place providing the incineration is conducted below a red heat. Pref- 

 erence, however, is given to the oxidation process, which uses nitric acid, owing 

 to its simplicity and rapidity of execution. He believes that milk contains more 

 phosphorus than the results already recorded show, and points out that there is 

 apparently a constant ratio between the phosphoric acid and the ash, and not 

 between the phosphoric acid and the proteins of the milk. Casein possibly does 

 not contain any phosphoric acid at all. 



The determination of phosphorus in milk, F. Bordas and F. Touplain 

 {Compt. Rend. Acad. Sci. [Pom], 1.52 {1911), No. 17, pp. 1127, ii28).— This is 

 a reply to Fleurent and Levi (E. S. R., 25, p. 411), in which the authors have 

 controlled the results obtained by their method (E. S. R., 25, p. 312) which de- 

 termines the phosphorus in the milk, serum, and coagulum. They do not believe 

 that there is any loss of phosphorus by the action of carbon on the phosphates 

 or the production of volatile phosphorus compounds with the fats. 



The authors point out that the addition of foreign substances, such as talcum 

 calcium and magnesium carbonate, barytes, etc., to the milk sample is not to 

 be recommended. 



The "neu-sal" milk test, J. Golding {Analyst, 36 {1911), No. Ji22, pp. 203- 

 206).— The "neu-sal " method (E. S. R., 23, p. 614) is stated to give satisfactory 

 results when the exact quantity of alcohol is used. 



" The fact that it is not pure fat which is being measured, but a solution, 

 the volume of which will vary with the quantity of alcohol used, makes the 

 method inferior in accuracy to the acid Gerber method, a fault which is likely 

 to be increased if it is put into the hands of inexperienced persons. On the 



