\<.KI< i !. I i RAL CHEMISTRY . 529 



omraende thai it be determined by difference. Tin' fad is recognized that the 

 errors introduced in the proposed methods of determining protein and cellulose 

 affecl the figures for nitrogen-free extract, as well as the calculated nutritive ratios. 



In general the author recommends thai the following components of feeding stuffs 

 be determined, viz, fat, albuminoids, sugar, starch, pentosans, ash, and water, with 

 cellulose and other nondeterminable substances grouped by difference. This scheme 

 of analysis has been in use in the chemical departmenl of the Copenhagen station 

 during recenl years. A number of analyses made by the proposed methods are 

 given. The bearing of these methods of analysis on digestion coefficients is dis- 

 cussed.— f. W. WOLL. 



Methods of estimating fat, < i. Rosenfeld {Centbl. Inn. Med., 1905, No. I i; abs. 

 in Biochem. Centbl. , 8 [1905), No. ?S, pp. 789, 740).— The author concludes, from a 

 study of different methods, that twice boiling with alcohol for a quarter of an hour 

 and extracting <i hours with chloroform is the mosl satisfactory method of estimating 

 fat. both as regards the quantity extracted and its freedom from nitrogen. 



The determination of fat and water in butter by the Gerber method, A. 

 Hesse {Mttchw. Zentbl, l {1905), No. 10, pp. 488-444)— The Gerber methods for the 

 rapid determination of fat and water in butter were tested and found, according to 

 the author, to he unsuitable for both control work and purposes of investigation. 



Tests of Sichler's "sin-acid" butyrometry, Lotterhos [Ztschr. Untersuch. 

 Nahr. u. Genussmtl.., 10 {1905), Xo. 10, pp. 596-599). — Comparative determinations 

 by the Sichler and gravimetric methods were made on milk, skim milk, buttermilk, 

 curdled milk, milk preserved with potassium bichromate, formaldehyde, and copper 

 sulphate, and .ream. The author concludes that the Sichler nonacid method in its 

 present form is <>f equal value to the Gerber acid method. 



The determination of the fat content of butter by the method of Gottlieb, 

 A. Burb {Ztschr. Untersuch. Nahr. u. Genussmtl., 10 {190.5), No. 5, pp. 286-290).— The 

 author considers the Gottlieb method of determining fat in milk applicable, with 

 more or less modifications, to all forms of dairy products. 



On the examination of curdled milk, vox Wissell {MUchw. Zentbl., I {1905), 

 No. 9, pp. 401-417). — Determinations of fat, total solids, and specific gravity were made 

 on sweet and curdled milk witli and without previous treatment with ammonia. 



The results for fat by the gravimetric method and the methods of Gottlieb and 

 I rerber showed practically no influence due to the souring of the milk or the addi- 

 tion of ammonia. Curdled milk rendered fluid by theaddition of ammonia showed, 

 however, too low a percentage of total solids and too high a specific gravity. It is 

 believed that these determinations may be corrected by adding 0.44 to the former 

 and deducting 0.001 from the latter. 



Contribution to the knowledge of sesame oil, II. Sprinkmeyee and II. Wag- 

 xkk {Ztschr. Untersuch. Nahr. u. Genussmtl., 10 {1905). No. >;, pp. 847-858). --Analy- 

 ses were made of samples of sesame oil from India, the Levant, and Africa. No 

 marked differences in chemical or physical properties were observed in the case oi 

 ■Unples from the first two sources. The African oil showed higher iodinand refrac- 

 fcometer numbers. A modification of the Baudouin test for the detection of sesame 

 oil in butter is described. 



The g-uaiac reaction of milk, A. A.RNOST {Ztschr. Untersuch. Nahr. u. Genussmtl., 

 10 {1905), No. 9, pp. 588-540). — The results of the author's investigations confirm 

 those of Neumann-Wender ami of Liebermann that the guaiac solution used in dis- 

 tinguishing raw from cooked milk becomes active after exposure to light and air. and 

 also the observation of Zink that the acetone solution gives a reaction even in a fresh 

 condition. 



The use of fermentation methods in the laboratory; a contribution to the 

 study of starch sirups, vox Raumeb | Ztschr. Untersuch. Nahr. ». Gi nu&mti., '■> {1905), 



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