AGRICULTURAL CHEMISTRY. 109 



book is intended as a laI)orator.v handbook for pharmacists, physicians, chem- 

 ists, milk analysts, and others who wisli to have at hand brief descriptions of 

 methods for the analysis of milk and milk products. The topics treated are 

 as follows : Characteristics of milk ; determination of milli constituents, includ- 

 ing urea, cholesteriu, lecithin, nuclein, and citric acid ; determination of the 

 freezing point and specific resistance of milk ; modification of milk as influenced 

 by heat, cold, electricity, disease, and other factors; detection of adulterations; 

 microscopical and bacteriological examinations; milk fi'om different animals; 

 butter and cheese; preparation of reagents; and extracts from French laws 

 relating to the sale and inspection of milk and milk products. 



A new method for the rapid analysis of milk, A. Rolet (Lait. et Indus. 

 Forme [/'ons], IV [I'JOD), Xo. 'i, pi). 25-27). — The author describes the method 

 proposed by Bordas and Touplain (E. S. R., 17, p. 335), and states that the 

 time required for milk analysis is mucli shortened l>y this method. 



Determination of proteins and formaldehyde in milk treated with formal- 

 dehyde, A. Agrestini (8taz. Sper. Agr. Ital., .',1 (1908), No. 8, pp. 520-529 ; abs. 

 ill Chcm. ZciithL, 1908. II, No. 19, pp. 161,0, 1GJ,1; Jour. Chem. Soc. [London^. 

 96 (1909), No. 556, II, p. 19.'/). — ^A discussion of methods. The mercury process 

 of Deniges is criticised. It is thought that a little 10 per cent solution of 

 hydroxylamin hydrochlorid should be added to samples of milk containing 

 formaldehyde before adding the mercury reagent. 



A new method for the calculation of the proteins in milk, G. A. Olson 

 (Jour. Indus, and Erigin. Cnem.. 1 (1909), No. Jf, pp. 253-256). — In this article 

 the ratio of protein to other milk solids is discussed. The author thinks that 

 this ratio is very constant, and may be considered as 1 : 1.34. " The protein 

 content of normal milk can be calculated with a fair degree of accuracy when 

 the total solids are known by the formula (TS) — TS/1.34=P. The percentage 

 of casein can be found by multiplying the percentage of protein by 0.8." 



The determination of sugar in cow's milk, H. J. Wusman and J. S. 

 Meulenhoff (PJiarin. WcekhL, ',5 (1908), No. J,2, pp. 1298-1305).— This is a 

 discussion of polarimetric methods of determining the percentage of lactose. 



The determination of milk sugar with ammonia-copper solution, Y. Shi- 

 MiDzu (Biochcni. Ztsclir., 13 (1908). No-. J-'/, pp. 2-',.3-261 ; <ibs. in MUchic. 

 ZenthL, 5 (1909), No. 2, p. 89). — The method recommended by the author is to 

 invert with hydrochloric or sulphuric acid and then titrate with ammouiacal 

 copper solution according to the Pavy-Kumagawa-8uto method. 



A comparison of methods for the preparation of milk serum, H. C. Lyth- 

 GOE and L. I. Xurenherg (Jour. Indus, and Engin. Chem., 1 (1909), No. 1, pp. 

 38-.'iO). — Various methods of preparing milk serum for the determination of the 

 index of refraction have been tested, with the following results : The asaprol 

 method is easiest of manipulation, gives the clearest serum, but decomposes 

 readily. The calcium chlorid method is difficult of manipulation and liable to 

 give a cloudy serum. The natural souring method is too slow for ordinary use, 

 but is a valuabk' method for use in hot weather. Four years' use of the acetic 

 method has shown it to be reliable, easy of manipulation, and giving concordant 

 results. 



On the value of reductase as a test for impurity of milk, C. Baethel 

 (Rev. Gen. Lait, 7 (1908), No.'i. 1, pp. 1-9; 2, pp. 25-33; 3, pp. .',9-56; abs. in 

 Hyg. Rundschau, 19 (1909), No. 1, p. 33). — From his experiments the author 

 concludes that reductase in milk furnishes a shorter means for judging as to 

 the bacterial content of milk than the fermentation test. Ten cc. of milk is 

 jtlaced in a tube and ()..". cc. of niethylene blue added, '1 cc. of liquid i)aratlin 

 being poured on top to pi-event contact with air. Sanitary milk will stand for 

 3 hours before it becomes discolored. 



