AGRICULTURAL CHEMISTRY AGROTECHNY. 17 



unavailable for the Graminea;, but when applied to phosphates which are ca- 

 pable of furnishing their phosphoric acid to the Graminese the reagent extracts 

 a considerable amount of phosiihoric acid. 



Ordinary phosphorites show only ti'aces of phosphoric acid with this method, 

 and the phosphorites from Singilei yield about 4 per cent of citrate-soluble 

 phosphoric acid, which is about one-fourth of all the phosj^horic acid present 

 in this fertilizer. Iron and aluminum phosphates are easily soluble in Peter- 

 mann's reagent while calcium phosi^hate is almost insoluble. 



The alundum crucible for the determination of phosphoric acid, G. Libeki 

 (Ann. R. 8taz. Chim. A&t\ Spc-r. Roma, 2. ser., 6 {1913), No. 2, pp. 247-255).— 

 It is concluded that the alundum crucible will be of service for the determina- 

 tion of phosphoric anhydrid as magnesium pyrophosphate. It is necessary, 

 however, to remove the impurities which are present in the crucible by wash- 

 ing with hydrochloric acid in order to obtain a comparatively constant weight. 



In regard to fertilizer analysis, E. A. Mitsciierlich and W. Simmermachek 

 (Zenthl. Kunstdiinger Indus., 18 {1913), No. 20, pp. 430, 431).— In a previous 

 communication one of the authors has pointed out that the methods for 

 judging a fertilizer and a soil should be founded on the same principles. 

 This is especially true because a fertilizer is only assimilable when it becomes 

 a part of the soil. As fertilizers when in the soil undergo a certain amount 

 of change, analyses lose some of their significance. The results obtained with 

 fertilizers in sand cultures, however, give figures which ai'e of physiological 

 and commercial value. 



The purpose of this work is to bring together or connect the figures obtained 

 for the solubility of fertilizers and those obtained in vegetative experiments 

 as a result of using fertilizer. The logarithmic formula of the law of minimum 

 is theoretically discussed and its validity is demonstrated from a practical 

 standpoint. The principles for a new method of chemical fertilizer analysis, 

 which depends upon the determination of the nutrient materials in the fer- 

 tilizer and the estimation of the saturation concentration of the nutrients in 

 water saturated with carbon dioxid at 15° C. are explained. The relation 

 between the plant physiological and chemical fertilizer analysis is shown. 



The determination of cellulose with nitric acid, V. Rao and B. Tollens 

 (In Festschrift zum s-iebzigstcn Gehurtstage van Jacob Esser. Berlin, 1913, 

 pp. 49-56). — The methods compared in this study were the Cross and Bevan, 

 Dmochowski and Tollens (E. S. R., 23, p. 417), and J. Konig and the materials 

 used were pure cellulose in the form of absorbent cotton, Swedish filter paper, 

 common filter paper treated by Henueberg's method with 1.25 per cent sul- 

 phuric acid and 1.25 per cent potassium hydroxid, sulphate cellulose, sodium 

 hydrate cellulose, crude wood fiber, jute, cacao shells, rice straw, wheat straw, 

 rye flour, oat flour, ground American white corn, buckwheat, cotton-seed meal, 

 marrow from Aralia papyrifera (which is used in China and Japan for making 

 paper), and cacao beans. With the cacao beans it was first necessary to 

 remove the fat when either the Cross and Bevan or the Dmochowski and 

 Tollens method was used. 



The Cross and Bevan method uniformly gave the highest results with 

 all materials except the marrow of A. papynfera, and these were not always 

 similar to those obtained by multiplying the results obtained by the Dmochow- 

 ski and Tollens method by 1.1. In some cases the factor was less than 1.1 

 and in others more. For jute and cereal straws it ranged from 1.16 to 1.38. 

 Nitric acid in some cases attacks the cellulose more than chlorin, which is used 

 in the Cross and Bevan method, but its employment is preferable since chlorin 

 affects the health of the laboratory workers. It is first necessary, however, 

 to establish the correct conversion factors. 



