616 EXPERIMENT STATION RECORD. 



On the compounds formed in the process of determining nitrogen accord- 

 ing to Kjeldahl, V. Andrlik ( VMriik III Sjrzdu. Vfslr. Pfir. IJk I'raze, 1901, p. 

 290; abs. in Chem. Ztg., 25 {1901), No. 60, Reperi., p. 221). — It is claimed that in the 

 Kjeldahl method not all of the nitrogen is transformed into ammonia, but a portion 

 remains as amin. This was found to be especially true in case of sugar-beet products 

 which contain betain. 



Determination of nitrogen in nitrates by the Schulze-Tiemann method, 

 V. Stanek {Bijhm. Ztschr. Zuckerind., 25 {1901), No. 7, pp. 356-358; ahs. in Joiir. 

 Soc. Chem. Ind., 20 {1.901) , No. 5, p. 506, fig. 1). — In the Schulze-Tiemann method the 

 nitric oxid is collected in a graduated tube over dilute alkali solution and the tube 

 is then transferred to a tall cylinder filled with recently boiled water and after a 

 time the volume and temperature of the gas are read off. The author has devised an 

 apparatus that avoids the transfer of the measuring tube containing the nitrit- oxid. 

 This apparatus is figured and described. 



On the determination of nitrates in potable waters with brucin and crys- 

 tallized formic acid, E. Cazeneuve and H. Defournel {Bui. Soc. Chim. Paris, 

 3. ser., 25 {1901), No. 12, jjp. 639, 640). — The method proposed is as follows: 

 When the water contains only a trace of nitrate evaporate 1 liter to dryness, take up 

 the residue in 20 cc. of distilled water, and evaporate to dryness again with 0. 05 gm. 

 of brucin in a small shalloAV dish, remove the dish from the water bath, and while 

 still hot add a few drops of concentrated formic acid and a little distilled water. A 

 yellow coloration appears, which, after standing 12 hours, is, on the addition of a 

 small quantity of hydrogen peroxid, changed to a rose color. By this means one 

 part of nitrate in 100,000 parts of water may be detected. Quantitative determina- 

 tions may be made by the colorimetric method. 



On the occurrence of free iodin in nitrate of soda, F. W. Dafert and 

 A. Halla {Zhrhr. Lundw. Vermclmr. OcMerr., 4 {1901) , No. 6, pp. 732-734).— U is stated 

 that free iodin is found in certain samples of sodium nitrate, resulting from the 

 decomposition of iodates present. 



A rapid method for the determination of arsenious oxid in Paris green, 

 S. Avery and H. T. Beans (./(>»/•. Anur. Clinn. Soc, 23 {1901), No. 7, pp. 485, 486).— 

 The authors offer the following rapid and accurate method for determining the 

 arsenic in Paris green: The sample is pulverized in an agate mortar and 0.2 to 0.3 

 gm. placed in a beaker of about 300 cc. capacity. About 25 cc. of water is added, 

 and concentrated hydrochloric acid, drop by drop, with constant stirring until 

 the green suspended is in solution; from (> to 10 drops are usually sutlicient. 

 Sodium carbonate solution is then added until a slight permanent jn-ecipitate is 

 formed and at this point 2 to 3 gms. of sodium potassium tartrate in solution added. 

 The tartrate will inmiediately dissolve the precipitated copper and prevent further 

 precipitation during the su))sequent titration. The whole is diluted to al)out 200 

 cc, solid sodium bicarbonate and starch solution added, and titrated with iodin in 

 the usual manner. The operation requires about 10 minutes. The end reaction is 

 sharp and is not obscured in the least by the blue color of the solution. 



On the elimination and quantitative estimation of water in oils, fats, 

 and waxes, C.B.Davis {Jour. Anwr. Clion. Soc, 23 {1901) , No. 7, pp. 487,488).— In 

 order to avoid loss by foaming and sputtering in drying oils, fats, and waxes, the 

 authors propose the following method: A coil of thick filter paper is placed in a wide- 

 mouthed weighing bottle and dried to constant weigiit. As much of the oil, fat, or 

 wax is introduc'cd as will l)e absorbed by the filter paper, the whole weighed, dried 

 to constant weight, and again weighed. 



Use of amyl alcohol in the analysis of fats, G. Halphen {Avn. Clii)ii. Analyt. 

 6 {1901), pp. 133-135; abs. in Jour. Chem. Soc. [London], 80 {1901), No. 463, II, p. 

 359). — The following method is given as being rapid and sufficiently accurate for 

 commercial purposes in estimating nonsaponitiable matter in fats: To 5 or 10 gms. 



