AGRICULTURAL CHEMISTRY. 411 



The authors describe numerous investigations which lead them to the conclu- 

 sion that the application of weak acid extractions in general and of citric acid 

 extraction in particular as a means of determining the fertility of soils and 

 of their responsiveness to fertilizers, does not have sufficient basis. — p. fireman. 



Determination of carbon dioxid, W. II. Waggaman (Abs. in Science, n, so:, 

 2C> (1007). Xo. 660, p. 2'/-'/). — This is an abstract of a paper read before the 

 Toronto meeting of the American Chemical Society, giving an account of a 

 modification of an a])paratus previously described by Cameron and Rreazeale 

 and of results obtained with it on a number of organic compounds and car- 

 bonate minerals. 



The determination of nitrogen in water by elementary analysis, M. 

 RuBNEB (Arch. Hyg., 62 {1901), No. 1, pp. 83-91).— As a result of tests of this 

 method the author proposes as a substitute for it a colorimetric modification 

 of the K.ieldahl method. 



A rapid method for the determination of calcium in water, and its sig- 

 nificance in connection with the analysis of water for boiler pui-poses, F. E. 

 Hale (Jour. Amer. Chem. fioc, 29 (1907), No. 7, pp. i 078-/ 08-5). —The method 

 proposed is an adaptation of the old and standard method based upon the pre- 

 (•!l)itation of the calcium as oxalate, the decomposition of the calcium oxalate 

 with sulphuric acid, and the titration of the liberated oxalic acid with potas- 

 sium permanganate. It is claimed that .the modified method is very accui'ate 

 and gives a complete analysis in 30 minutes. 



" The method is admirably suited for the routine analysis of large numbers 

 of samjiles, may be considered accurate to 2 parts per million, is applicable to 

 all quantities of calcium including that of sea water, is equally accurate with 

 large and small quantities of calcium, furnishes, in eonibination with the soap 

 method, a rapid method of determining the total magnesium, and hence is ex- 

 tremely valuable in the rapid analysis of mineral and boiler waters." 



Determination of the hardness of water, P. Nawiasky and S. Korschux 

 (.4 /•(■/(. Hyg.. 61 (1907). No. .',. pp. 3-'fS-35-'f ; ahs. in Jour. Chem. Soc. ILon- 

 don], 92 (1907), No. 537, II, p. 579). — The authors recommend and describe 

 Pfeiffer's methods for temporary and total hardness and Monhaupfs method 

 for magnesia. 



The determination of manganese in water, I\. S. AVeston (Jour. Antcr. 

 Chem. Sac, 29 (1907), No. 7, pp. 1074-1078).— -The author describes and rec- 

 ommends a modification of Schneider's method, which is based upon the fact 

 that in the presence of an excess of nitric acid a manganous salt is oxidized 

 to permanganic acid by bismuth tetroxid. 



Swiss food book (^ckweizcriftches LehenHinittrlhuch. Bern, 1906, 2. rev. ed., 

 pt. 3, pp. IX+95; rev. in Hyg. Rundschau, 17 (1907), No. 17, pp. 1053-1055).— 

 Official methods for the examination of meat and meat products, legumes and 

 products made from them, bread and other flour products, spices, coffee and 

 coffee substitutes, tea, cocoa, and chocolate. 



Food inspection methods of analysis (Jour. Off. Repuh. Franc, 39 (1907), 

 No. 193, pp. 5032-503.'i). — Official methods are given for the examination of 

 cider, perry, flour, and meal, for the detection of tin in cakes and molasses, and 

 for the detection of preservatives and artificial sweetening substances. 



Preserved vegetables containing copper and its estimation, C. Brebeck 

 (Ztsrhr. Untersuch. Nahr. u. acnussmil, 13 (1907). No. 9, pp. 5 ',8-5 5 2). —In 

 the method which the author outlines for determining copper in vegetables, 

 the material is incinerated, evaporated with hydrochloric acid, treated with 

 ammonia, and the copiier precipitated in a platinum dish by inserting a strip 

 of pure zinc. He states that metallic coi)i»er adhei"es firmly to the platinum. 



