AGRICULTURAL CHEMISTRY AGROTECHNY. 805 



caused a loss in carnosin, and the use of lead salts involved a decrease in 

 carnitiu and had very little effect on increasing the yield of niethylguanidin. 



The quantitative determination of the amino acids of feeding stuffs by the 

 Van Slyke method, H. S. Grindley et al. {Jour. Amer. Clicm. Soc, 37 (1915), 

 No. 7, pp. 177S-1781).—The object of this work was to determine quantitatively 

 the amino acid content of feeding stuffs, those used being cotton-seed meal, 

 tankage, and alfalfa hay. Consistently low percentages of amino acid nitrogen 

 were found as compared with the results obtained by Van Slyke (E. S. It., 31, 

 p. 610) with isolated proteins. 



"A study is also being made of the free amid and the free amino acids of 

 feeding stuffs, with the object of determining to what extent, if any, the so- 

 called nonprotein nitrogenous substances affect the quantitative determination 

 of the amino acids of feeding stuffs by the Van Slyke method. 



"It is evident from the results given that there are marked differences in 

 the amino acid content of the three feeding stuffs here reported. Hence, it is 

 logical to suppose that the feeds would have a widely different nutritive value, 

 particularly as supplements to such feeds as corn. 



"The quantitative determination of the amino acids of feeding stuffs, to- 

 gether with the aid of the rapidly increasing evidence on the nutritive functions 

 of the amino acids, will make it possible to extend our present knowledge of 

 feeding stuffs." 



Changes in the fat content of feces preserved by freezing without the 

 addition of a preservative, C. A. Smith, R. J. Miller, and P. B. Hawk (Jour. 

 Biol. Chem., 21 (1915), No. 2, pp. 395-401) .—Analyses of feces before and after 

 freezing at —12° C, it is concluded, show that simple freezing without the addi- 

 tion of a preservative is not applicable to the preservation of feces in which fat 

 is to be determined. The fat of feces kept at a temperature of —12° C. under- 

 goes both hydrolysis (shown by increase in fatty acid) and actual destruction 

 (shown by decrease in total fat). 



Food chemistry in the year 1913, J. RIjhle (Ztschr. Angew. Chem., 27 

 (1914), No. 92-93, Aufsatzteil, pp. 617-624; 94-95, pp. 625-630).— A retrospect 

 of work done during 1913, dealing with methods of food analysis and the com- 

 position of foods. 



Tamarind sirup, W. C. Taber (Jour. Indus, and Engin. Chem., 7 (1915), 

 No. 7, pp. 607-609). — The published analyses of tamarinds agree fairly well 

 as to the amount of tartaric acid present. Fruit examined in the Bureau of 

 Chemistry of this Department which was purchased in the New York market 

 had an acidity of 10 per cent calculated as tartaric acid. A large quantity of 

 the acidity was due to tartaric acid and the rest to undetermined acids. No 

 citric acid was found in the sirups made from the fruit. 



" The manufacturing process employed in making [true] commercial tamarind 

 sirups consists simply in making a water extract of the tamarinds by adding 

 water to the fruit, heating the mixture for a few hours, filtering it, and adding 

 sugar until a solid content of approximately 60 per cent is obtained. . . . 



" The formulas used for making the true tamarind sirup vary somewhat in 

 the amount of fruit used, some manufacturers using as much as 30 to 35 per 

 cent." 



The results of an examination (chemical and organoleptic) of six samples 

 of tamarind sirup prepared in the Bureau of Chemistry are given. 



Home canning of fruits and vegetables, F. J. Ceider (South Carolina Sta. 

 Circ. 27 (1915), PP- 15). — This publication gives specific directions for home 

 canning of fruits and vegetables by fractional sterilization, open kettle, and 

 steam pressure methods. Canning recipes are included. 

 18522°— No. 9—15 2 



