936 EXPERIMENT STATION KECUKD. 



raw bone meals. . . . With the free acid the solubilities are in the order of the 

 strength of solution without exception. 



"(2) The presence of free ammonia in the citrate solution lowers the solubility 

 and the amount of lowering varies with different products. . . . 



"(3) Bones of similar chemical composition and physical properties, and contain- 

 ing practically the same percentage of total phosphoric acid, have different solu- 

 bilities in the same citrate or citric-acid solution. . . . This observation leads one to 

 infer (a) that the action of the solvent is either not one of simple solution, or (b) 

 that there is a fundamental difference in the phosphates of the bones." The latter 

 view is said to be in accord with that of Gebek (E. S. R., 6, p. 398). 



The determination of phosphoric acid in Thomas slag-, bone meal, etc. , O. 

 B iTTCHER (Chem. Ztg., 29 (1905), No. 100, pp. 1293, 1294; abs. in Chem. CentbL, 1906, 

 I. No. 4, p. 282). — The author summarizes data obtained in over 800 analyses of 

 Thomas slag to show that his method of determining the citric-acid soluble phosphoric 

 acid in Thomas slag (E. S. R., 15 p. 744) gives reliable results when carried out 

 promptly and with proper precautions. Data are also reported to show that the 

 German official method for determining total phosphoric acid in Thomas slag, bone 

 meal, etc., gives reliable results and that it is not necessary, as claimed by Schenke, 

 to neutralize the solution before precipitation, whether nitric acid or sulphuric acid 

 has been used for preparing the solution of the phosphate. 



Analytical notes on the superphosphate industry, L. Schucht (Ztschr. Angew. 

 Chem., 19 (1906), pp. 183-187; abs. in Chem. CentbL, 1906, T, No. 10, pp. 870, 871; Bui 

 Soc. Chim. Paris, 3. ser., 36 (1906), No. 5, p. 558; Analyst, 31 (1906), No. 361, p. 129).— 

 Drying at 100° C. for 3 hours gives inaccurate results for moisture. Better results 

 were obtained by exhaustion of 2 gm. on the filter with absolute alcohol and ether 

 and weighing the evaporated extract after heating to 120° for 3 hours and the residue 

 on the filter after heating to 40° until the ether disappears. 



The author defends his oxalate method of determining free acids against W. 

 Moller's criticism that it gives too low results and is less accurate than the method of 

 alkalimetric titration, reporting further tests which bear out his contention. He 

 condemns the sugar inversion method. The examination of silico-fluorids by titra- 

 tion with one-half normal alkali and phenophthalein and methyl orange is discussed. 



Use of the Heraeus electric crucible in the analysis of phosphates, F. Hauss- 

 ding (Chem. Ztg., 30 (1906), No. 7, pp. 60, 61; abs. in Bid. Soc. Chim. Paris, 3. ser., 36 

 (1906), No. 4, p. 430; Analyst, 31 (1906), No. 361, p. 128, fig. 1).—A crucible is described 

 with which it is possible with addition of magnesia to calcine organic phosphates in 

 two minutes. The crucible is also useful for igniting ammonium-magnesium phos- 

 phate precipitates. 



The industrial analysis of water, E. Bosch (Ztschr. Angew. Chem., 19 (1906), 

 pp. 92-95; abs. in Bui. Soc. Chim. Paris, 3. ser., 36 (1906), No. 5, p. 555).— The author 

 discusses various methods of industrial analysis of water and proposes to test for 

 presence of magnesium and sodium sulphate by adding barium carbonate and phe- 

 nolphthalein and boiling, the production of a decided coloration indicating that the 

 sulphuric acid is in part combined with magnesium and sodium and not entirely in 

 form of calcium sulphate. 



The determination of nitrous acid in water analysis, G. Lunge (Ztschr. 

 Angew. Chem., 19 (1906), No. 7, p. 283).— The author calls attention to the fact that 

 some analysts have confused his method for the detection of nitrous acid in sulphuric 

 acid with the colorimetric method proposed by him for the determination of nitrites 

 in water. « In the latter case no sodium acetat ' is used with the "Lunge reagent" 

 (a mixture of an acetic-acid solution of a-naphthylamin and a water solution of sulfa- 

 nilicacid). 



« Ztschr. Angew. Chem., 7 (1894), p. 348, 



