322 EXPERIMENT STATION RECORD. 



VilHers' method by saturating the solution with nitric acid, adding 0. 

 gm. of manganese sulphate or nitrate and heating gently, adding more 

 nitric acid from time to time as the evolution of gas ceases. Vanadyl 

 dichlorid (VaO Cl 2 ) is suggested as a substitute for the manganese 

 salts. 



A reaction for nitrous acid, E. Riegler (Pharm. Centralhdlle, 

 (1897), p. 191; dbs. in Ghem. ZUj.. 21 (1897 ), No. 35, Bepert.,p. 99).— -To 1; 

 cc. of the solution to be tested add 0.02 to 0.03 cc. of a mixture of equal 

 parts of naphtionic acid and pure /i-naphthol and 2 or 3 drops of con- 

 centrated hydrochloric acid, and shake vigorously for a minute. Ilolc 

 the test tube in a slanting position and pour in 1 cc. of ammoniur 

 hydrate. If nitrous acid is present a red ring is formed, and this colora- 

 tion is imparted to the whole solution when it is shaken. One part of 

 nitrous acid in 1,000,000 of water is sufficient to give the reaction. 



The phloroglucin method for the estimation of pentosans, J. B. 

 Lindsey and E. B. Holland (Massachusetts Hatch Sta. Rpt. ls'it;, 

 pp. 97—99). — The phloroglucin method for the estimation of pento- 

 sans, suggested by Couucler 1 and modified by Kruger and Tollens, 2 of 

 which a description is given, was compared with the method employing 

 phenylhydraziu. Determinations were made by both methods with 

 English hay, high-grown salt hay. branch grass, low meadow fox grass, 

 Buffalo gluten feed, and lupine seed. "With two exceptions, the 

 two methods show very closely agreeing results. We propose to still 

 further compare these methods in the near future. The phloroglucin 

 method, on account of its greater simplicity, is much to be preferred." 



New distinguishing characteristics of butter and margarin, J. 

 Hoffman (Ckem. Ztg., 21 (1897), X<>. 57, pj>. 571, 572, fig. l).— The two 

 fats are dissolved in ether, and drops of the clear solutions are allowed 

 to fall upon glass plates. The residue of margarin left after the evapo- 

 ration of the ether is in the form of a disk with a sharply serrated 

 edge, while that from butter shows a wavy edge without being dis- 

 tinctly serrated. The distinction is sharper when alcohol is added to 

 the ether solutions. 



A method of determining butter and margarin and mixtures of the 

 two in an exact way is proposed, which depends on the difference in 

 the degree of solubility of these substances in absolute alcohol. Butter 

 dissolves more readily than margarin, and mixtures of the two give 

 corresponding intermediate results. — J. t. Anderson. 



Sonie remarks relative to the carbohydrates of agricultural plants and seeds, 

 J. B. Lindsky {Massachusetts Raich Sta. Up/. ISOO. pp. 90, 91.) — This article contains 

 brief statements concerning the presenl knowledge of the composition of crude liber 

 ami extract matter. 



Researches on phosphoric acid: Determination of pyrophosphoric acid, Ber- 

 thelot and Andre (Ann. Chim.etPhys., 7. sir.. /// (1897), June, pp. 184-189). — Sec also 

 Coinpt. Rend. Acad. Sci. Paris, 123 (1896), p. 773 (E. S. R., 9, p. 23). 



' Cheni. Ztg., 18 (1894), p. 966 (E. 8. R.. 6, p. 189). 

 *Ztschr. angew. Chein., 1896, p. 33 (E. S. R., 7, p. 830). 



