706 EXPERIMENT STATION RECORD. 



in solutions of phenols such <is resorcin, hydroquinon, and ordinary phenol. The 

 best results, however, may be obtained with ordinary phenol, which gives a 

 permanent solution and one in which it is possible to titrate the alkali with 

 standard hydrochloric acid. Carbonates, phosphates, silicates, and aluminum 

 and iron oxids are insoluble in phenol. 



The results with the method agree well with those obtained by the usual 

 gravimetric methods. The use of the method for examining milk of lime in 

 sugar retineries is discussed. 



The detection of inferior ammoniates in commercial fertilizers, J. P. Street 

 {Jour. Indus, and Engin. Chem., 2 {1910), No. 7, pp. 311-313). — This article has 

 particular regard to the detection of inferior inert nitrogen fillers, e. g., some 

 peats, and gives the method in use at the Connecticut State Station, which is 

 as follows : 



" Weigh on to a moistened 9 cm. S. and S. No. 595 filter a quantity of the 

 fertilizer equivalent to approximately 45 mg. of organic nitrogen and wash with 

 water at room temperature to about 200 cc. Transfer filter and contents to a 

 300 cc. low-form Griffin beaker, and digest with 125 cc. of 1.6 per cent neutral 

 potassium permanganate solution in a hot water bath for 30 minutes. Set 

 the beaker down in the bath so that the surrounding water shall be higher than 

 the solution in the beaker, cover with a watch-glass, and stir twice at intervals 

 of 10 minutes with a glass rod. At the end of the digestion remove from bath, 

 add 100 cc. of cold water, and filter through a heavy folded filter. Wash with 

 cold water, small quantities at a time, until the total filtrate amounts to 400 cc. 

 AVhen sufficiently dry to handle, transfer filter and contents to a nitrogen flask 

 and determine nitrogen by the Kjeldahl method. The nitrogen obtained, less the 

 blanks from the two filters used, is the nitrogen not oxidized by the perman- 

 ganate." 



In regard to magnesium, ammonium phosphate, K. Bube {Ztschr. Analyt. 

 Chem., J,9 {I'JIO). Xo. 9-10, pp. 525-596, pis. 6, fig. /).— This contains a critical 

 review of practically all the previous work, and a study in regard to magnesium 

 and ammonium phosphate with particular reference to the estimation of mag- 

 nesium and phosphoric acid as a magnesium annnonium pliosi)hate. 



Analysis of sulphur for agricultural purposes, A. Bruno (Ahs. in Ann. 

 i'liim. Analyt., 15 {1910). Xo. 6, pp. 235, 23ii). — A description of the methods 

 of analysis and judging of sulphur which is to be employed for agricultural 

 inir poses. 



Determining sulphuric acid by the benzidin method, particularly in the 

 presence of chromium, G. von Knorre {Ztschr. Analyt. Chem., 49 {1910), No. 8, 

 pp. 461-lf8-'t). — The results show that benzidin can be protected from the oxidiz- 

 ing action of chromic acid in the same manner as from ferric salts, namely, by 

 adding hydroxylamin hydrochlorid to the reagents. To prevent a precipitation 

 (if benzidin chromate when potassium bichromate is present, the author recom- 

 mends rendering the solution acid with hydrochloric acid. In the presence of 

 chromic chlorid the reaction is not quantitative, and heating the solution brings 

 about the formation of complex chromium-sulphuric acid compounds. If, how- 

 o\er, the solution is boiled with an excess of sodium acetate or, better, with 

 ammonium formate, these complex combinations are decomposed and it is pos- 

 sible to determine sulphuric acid with benzidin hydrochlorid quantitatively. 



The author points out that Friedheim and Xydegger's results « with this 

 method in the presence of ferric salts are directly opposite to those obtained b.y 

 Kaschig (E. S. R., 15, p. 337) and the author. 



o Ztschr. Angew. Chem., 20 (1907), No. 1, p. 9. 



