AGRICULTURAL CHEMISTRY. 7 



On the estimation of free acid and its relation to total acidity in super- 

 phosphate, .1. Obtersetzer ( Chem. Neiv8 } 91 (1905), No. 2872, p. 215). — The method 



of using alizarin sulpl ic acid as an indicator in the determination of free acid in 



superphosphates is briefly described. 



The determination of perchlorates, M. DlTTRlCH and II. Bolleneach /'■ 

 Deut. Chem. Gesell., 88 (1905), pp. 751, 752; abs. in Jour. Chem. Soc. [London], 88 

 (1905), No. 510, 11. p. 281). — In the method proposed the perchlorates are reduced 

 to chlorids by fusion in sodium nitrite. 



The determination of perchlorates and chlorates in sodium nitrate, 

 D. T» hernoba jeff ( Chem. Ztg., 29\ 1905), No. 82, pp. 442,448). From investigations 



which an- reported the author ivr mends thai chlorates and perchlorates be 



determined together by Lemaitre's method of reduction with sodium sulphite, and 

 the chlorates be determined separately by reduction in the cold by means of iron 

 and Bulphuric acid according to Hendrixson's method. 



Contribution to the analysis of nitrate of soda, R. Bensemann i Ztechr. Angew. 

 Chem., 18 (1905), No. 21, p. 816). A form of an old method based on reduction with 

 oxalic acid and fusion until carbonate is formed and nitrogen and chlorin are expelled 

 is described and comparisons of it with the Hamburg met hod are reported. 



A new method of determining- magnesium carbonate in limestones, \Y. F. 

 Koppesch aar (Ztschr. Analyt. Chem., 44(1905), No. 8-4, pp. 184-187, figs. 8). — The 

 method described is based upon the fact that when limestone is dissolved in the least 

 possible amount of hydrochloric acid and the Lime precipitated as sulphate by adding 

 concentrated sulphuric acid the magnesia remains in solution. The filtrate there- 

 fore contains relatively a large amount of magnesia and a small amount of lime which 

 can be precipitated as calcium oxalate almost free from magnesia. 



Notes on the determination of nitrous acid, especially by the Trommsdorff 

 method, H. Legler (Pharm. Cenlralhalle, 46 (1905), pp. 181-188; abs. in Chem. 

 Centbl., 1905, I. No. 14, P- 1048). — Precautions to be observed and apparatus to be 

 used in order to secure accurate results are described. 



The electrolytic estimation of small amounts of arsenic, C. M \i and II. 

 Hurt (Ztschr. Untersuch. Nahr. u. Gemmmtl., 9 (1905), No. 4, pp. 198 199, Jig. 1).— 

 An improved method of estimating arsenic electrolytically is discussed. 



The determination of boric acid, K. Windisch (Ztschr. Untersuch. Nahr. u. 

 GenussmU., 9 1 1905 ), No. //, pp. 641 -660).— This is a review of the different methods 



which have been proposed for the determinate f boric acid, the foot-notes consti- 



tutinga bibliography of the literatureof thissubject. Results obtained bythe author 



with some of these methods are reported. 



Gasometric determination of formaldehyde, < i. B. Frankforter and R. W1.-1 

 (Jour. Amer. Chem. Soc., 27 1 1905), No. 6, pp. 714 -719 t fig. 1).— This method is based 

 upon the fact that when potassium hydroxid is added to formaldehyde in the pres- 

 ence of hydrogen peroxid free hydrogen is liberated. The substitution of sodium 

 peroxid for hydrogen peroxid gave slightly higher results. 



The detection of hydrogen peroxid in milk, Qtz (MUchw. Z< rUbl., 1 ( 1905 I, No. 

 4, pp. 175—178). — The author's experiments confirm the claims made for titanic and 

 vanadic acids as suitable reagents for the determination of hydrogen peroxid in milk. 

 The reaction may be obtained whether the milk is heated or not before the addition 

 of the hydrogen peroxid. The hydrogen peroxid may be detected for a much longer 

 period when the milk is heated before the preservative is added. An increase in 

 temperature hastens the decomposition of the hydrogen peroxid. 



The determination of water in foods and physiological preparations, F. <J. 

 Benedict and Charlotte R. Manning (Amer. Jour. Physiol., 18(1905), No. 8, pp. 

 809-829). — From comparative studies of different methods the conclusion was reached 



4393— Xo. 1—05 2 



