206 EXPERIMENT STATION EECORD. 



" Results on many organic ammouiates in presence of acid ptiosphate are 

 given, sliowing tliat tlie method does differentiate between higli and low-grade 

 materials." 



Activity of organic nitrogen as measured by the alkaline permanganate 

 method, C. H. Jones {Abs. in Science, n. ser., 35 {1912), No. 898, j)p. 426, 427).— 

 After giving a detailed description of the alkaline permanganate method 

 and the form now used for reporting the results, the author reports results on 

 14 different crude nitrogenous stock samples, S commercial fertilizers, ;md 13 

 mixtures of known composition, and interprets them from a standpoint of nitro- 

 gen activity. 



" A method is also presented for determining the percentage of ' nitrogen in 

 the organic and volatile matter.' Its application to fertilizers and crude stock 

 as a means of determining whether the organic nitrogen present came from 

 materials rich or poor in that element is discussed." 



A method for determining phosphoric anhydrid colorimetrically, N. Pas- 

 BEEiNi {Staz. Spcr. Agr. ItaJ., //-) {1911), No. 1, pp. 5-10). — Previously noted 

 from another source (E. S. R., 25, p. 614). 



A rapid volumetric method for the estimation of free sulphur, C. Davis 

 and J. L. Fotjcar {Jour. 8oc. Chem. Indus., 31 {1912), No. S, p. 100).— The 

 method is as follows: 



"One gm. of the finely ground (60 mesh) sample (or its equivalent if pre- 

 viously dried) is dried in the water bath for an hour (if not already dried) 

 and then transferred to a 250-cc. flask ; 1.5 gm. of sodium cyanid and 50 cc. of 

 absolute alcohol are added, and the contents are boiled under a reflux condenser 

 for 2 hours. The alcohol is then completely removed by distillation, 100 cc. 

 of hot water added, and the solution washed into a 250-cc. flask. The volume 

 is made up to the mark — in the cold. To 25 cc. of this solution 75 cc. of water 

 and 5 cc. of saturated iron alum solution are added; this is heated with con- 

 stant stirring to 95° C, filtered into a 750-cc. beaker, and washed free from 

 thiocyanate. When cool, 5 cc. of nitric acid is added, the solution made up, 

 if necessary, to about 500 cc. with water, and titrated with twentieth-normal 

 silver nitrate solution until the red color of the ferric thiocyanate completely 

 disappears, or an excess of silver nitrate may be added and the solution 

 titrated back with twentieth-normal thiocyanate. Should the sample contain 

 thiocyanate, as is most likely in the case of si>ent oxid, a blank test should be 

 conducted, the thiocyanate being extracted with water. 



" Should it be required to ascertain the amount of matter, other than sulphur, 

 soluble in carbon bisulphid, it may be determined by subtracting the sulphur 

 content, found as above, from the figure obtained in the usual way for the 

 percentage soluble in carbon bisulphid." 



Detection of fluorids, E. Rupp {Ztschr. Untersiich. Nahr. u. Genussmtl., 22 

 (1911), No. 9, pp. 496, J,97, fig. 1; abs. in Analyst, 37 {1912), No. 430, p. 32).— 

 The substance to be tested is converted into ash and moistened in a platinum 

 or lead crucible with 3 drops of water and 1 cc. of sulphuric acid. The crucible 

 is then pitted loosely with a rubber stopper, through which a piece of glass 

 rod passes. The lower end of the glass rod is moistened with a drop of water 

 and the crucible with its contents heated for about 20 minutes. 



If fluorids are present the rod becomes coated with a film consisting of silica, 

 sodium silicofluorid, and calcium silicofluorid. If only traces of fluorid are 

 suspected the portion of the glass rod below the stopper may be covered with a 

 piece of rubber tubing, leaving only the end exposed to the action of the vapors. 



Work published in regard to the composition, analysis, and adulteration 

 of foods, A. J. J. A^\NDEVELDE {Repevt. Internat. Comp., Anal, et Falsif. Denr^es 

 Aliment., 10 {1909), pp, 104). — This is a bibliography, which in some instances 



