OHEMTSTRY. 953 



pp. 289-313, jxgs. 3). — This is the detailed report of investigations on the determina- 

 tion of sulphur in organic su])stances, tlic <f(>neral results of which are noted above 

 from ani>thcr sourci>. 



Contributions from the agricultural chemical laboratory at Gottingen, 15. 

 ToLLENS [Jour. Laiidw., 51 [1903], No. 4, pp- 355-369). — This is a brief summary of 

 the numerous contributions from this laboratory which have appeared during the 

 last 10 or 12 years. 



Ash in feed stuflFs, :\I. Havenhill [Iowa Agr., 4 {1904), No. 6, pp. 230-233).— 

 A compilation of analyses with a discussion of the function of the ash constituents in 

 nutrition. 



The precipitation of magnesium oxalate with calcium oxalate, N. Kniuht 

 [Cheui. News, 89 [1904), No. 2313, pp. 146, 1-^7).— Analyses of dolomite rock by differ- 

 ent students are reported, w'hich show that the amount of magnesium oxalate which 

 will be precipitated with calcium oxalate varies from an almost inappreciable amount 

 to a considerable quantity. In the author's opinion " it is therefore always better to 

 dissolve the unwashed precipitates of calcium and magnesium in warm hydrochloric 

 acid, then to add ammonia to precipitate the calcium. After standing a suitable time, 

 the calcium may be filtered, and the filtrate can be added to the solution containing 

 the main portion of the magnesium, or the two portions can be separately treated." 

 A new method for the determination of free lime and on so-called ' ' dead 

 burnt" lime, E. H. Keisek and 8. W. Forder [Amer. Chem. Jour., 31 [1904), No. 2, 

 pp. 153-162, Jig. 1). — The method proposed is carried out as follows: 



Heat 0.2 to 0.5 gm. of the material in a platinum crucible to drive off moisture, or 

 in case of cements, heat over a blast lamp for a few minutes to expel carbon dioxid, 

 cool in a desiccator, and weigh. Add a few drops of recently boiled distilled water 

 and place the crucible in a brass protector consisting of a cylindrical box provided 

 with a screw top carrying a brass inlet and outlet tube, the thread of the cap being 

 made air-tight witli a little white lead and oil. Place the protector in an air bath 

 and raise the temperature to 85° C, allowing it to remain at this point for 30 min- 

 utes. Draw a slow current of air freed from carbon dioxid and moisture through 

 the apparatus and raise the temperature to 185° C, maintaining the temperature at 

 this point for 30 minutes. Cool the crucible in a desiccator and weigh, the increase 

 in weight giving the amount of water taken up by the quicklime to form calcium 

 hydroxid. 



Satisfactory tests of the method with different materials under a variety of 

 conditions are reported. 



A portable outfit for the determination of carbonic acid, dissolved oxygen, 

 and alkalinity in drinking water, F. B. Forbes [Jour. Ainer. Chem. Soc, 26 

 [1904), No. 4, pp. 382-388, Jig.'i. 3). — Outfits for determination of dissolved oxygen by 

 the Winkler method, free carbonic acid l)y Seyler's method, and alkalinity or fixed 

 carbonic acid by Hehner's method are described. 



Sprengel's method for colorimetric determination of nitrates, L. "\V. 

 Andrews [Jour. Amer. Chem. Soc, 26 (1904), No. 4, pP- 388-391).— T\\\^ article 

 briefly reports experiments in which it was shown that the yellow color obtained in 

 Sprengel's method is not due to the formation of picric acid but to paranitrophenol. 

 The determination of nitrogen in food materials and physiological prod- 

 ucts, H. C. Sherman, C. B. McLaughlin, and E. Ostekuerg [Jour. Amer. Chem. 

 Soc, 26 (1904), No. 4, jjp. 367-371).— In tests with 17 animal and vegetable sub- 

 stances several modifications of the Kjeldahl method were comi)ared as regards the 

 time required for the complete transformation of the nitrogen. 



When the sample was digested with sulphurii', acid and mercury or with sulphuric 

 acid and potassium sulphate, the transformation of the nitrogen was rarely complete 

 when the solution became colorless or of a faint straw color. Continuing the diges- 



