AGRICULTUEAL CHEMISTRY AGROTECHNY. 713 



A large number of estimations made with the leaves of different plants (man- 

 golds, turnips, Tropwolum majns, Helianthus, carrot, potato, etc.) showed 

 the percentage of pentose obtained by the distillation method, when applied to 

 the alcoholic extract treated according to the author's scheme of analysis, to 

 range from 0.3 to 1 per cent, calculated on the total vacuum-dried matter. Tests 

 were also carried out with sugars. 



In reg'ard to the utility of the Tollens-Kriiger method for estimating 

 pentosans, O. Fallada, E. Stein, and J. Ravnikak (Osterr. Ungar. Ztschr. 

 Zxiekerindus. u. Landio., 43 (1914), No. 3, pp. 425-432). — Crystalline sucrose 

 submitted to test by the phloroglucin method yielded a higher amount of 

 furfurol than previously reported by Andrlik.** This is probably due to the 

 fact that an oil bath with a higher temperature (155° C.) was used in the op- 

 eration. When the distillations were conducted under uniform conditions, con- 

 trary to Andrlik's opinion uniform results could be obtained if amounts of 5 gm. 

 sucrose were used for the determination. Above this point ununiformity of 

 results began. 



Dextrose and levulose when used in the proportion yielded when 10 gm. of 

 sucrose is hydrolyzed gave 107.4 mg. of phloroglucin, and about the same 

 amounts when treated separately. 



Another precipitation method, that of Jager and linger with babiturenic acid,* 

 was also studied. Babiturenic acid in warm 12 per cent hydrochloric acid 

 yields a condensation pi-oduct with furfurol. In this method the pentosan 

 determination is carried on as in the phloroglucin procedure save that the dis- 

 tillation should be carried quickly to a point of 400 cc. of distillate. The 

 babiturenic acid yielded lower results for furfurol than the phloroglucin method, 

 but it is thought that it should be studied further, as the results obtained with 

 it are deemed more exact. 



The present position of the chemistry of starch, H. Pkingsheim {Landw. 

 Yers. Stat., 84 {1914), No. 3-4, pp. 267-282).— A digest of the literature. 



Determination of calcium in solid substances and fluids derived from the 

 animal organism, S. Gutmann {Biochem. Ztschr., 58 {1914), No. 6, pp. 4^0, 

 471). — In Aron's method (E. S. R., 19, p. 1009) in which the calcium salts are 

 precipitated by alcohol after destruction of the organic matter by a nitric- 

 sulphuric acid mixture, some of the calcium sulphate adheres to the walls of 

 the flask. This error may be obviated if alcohol is added after eliminating 

 the excess of nitric acid and the precipitate is filtered off after standing until 

 the next day. The precipitate thus obtained is returned to the flask and dis- 

 solved in a 10 per cent sodium carbonate solution and heated for one-half hour. 

 The carbonate formed is dissolved in acetic acid and the excess of acid neutral- 

 ized with ammonia, when the calcium is precipitated in the usual manner as 

 calcium oxalate. 



A method for determining small amounts of boron in organic materials, 

 G. Berteand and H. Agulhon {Ann. Falsif., 7 {1914), No. 67, p. 223).— A cor- 

 rection to the work previously noted (E. S. R., 32, p. 206). 



Bapid detection for quantitative estimation of small amounts of esterase, 

 A. Bach {Fermentforsch., 1 {1915), No. 2, pp. i5i-J54).— Tyrosinase is a 

 mixture of amino acidase and ordinary phenolase. The latter does not oxidize 

 tyrosin as such, but only after it has been converted by amino acidase into 

 paraoxyphenyl acetaldehyde, ammonia, and carbon dioxid. As phenol esters 



o Zeitschr f. Zuckerinclustrie in Pohmen. XXXIII, 1898-99, p. 314. 



"Ber. Deut. Chem. Gesell., 35 (1902), No. 20, pp. 4440-4447; 36 (1903), No. 6, pp. 

 1222-1229. 



