2^24 EXPERIMENT STATION RECORD. 



yields a dense reddish-brown precipitate, to which the formula Mo (OH)^ is assigned. 

 This jirecipitate dissolves in sodium carbonate solution, and when this is exactly 

 neutralized with nitric acid and heated the yellow phosphomolybdic compound 

 separates out. 



Double ammonium phosphates in analysis, Martha Austin {Amer. Jour. 

 Sci., 4. scr., 4 {1903), No. SO, -pp. 150-160). — The author briefly reviews her own 

 work (E. S. R., 10, p. 419) and that of other investigators relating to the accuracy 

 of the determination of magnesium, manganese, cadmium, and zinc by means of 

 double ammonium i)hosphates, and calls attention to certain precautions which 

 must be observed to insure accuracy, especialh^ the use of anhydrous asbestos in 

 filtering. The results obtained by Miller and Page « in the determination of cadmium 

 are stated to be unreliable by reason of their use of hydrous (serpentine) asbestos. 

 The modification of the author's method for the determination of zinc and manga- 

 nese proposed by Dakin'' is criticized as inaccurate on account of the error introduced 

 by washing with ammonium i)hosphate and alcohol and by the use of hydrous 

 asl)estos in filtering. 



Rediscovery of a process for rendering phosphoric acid available, C. 

 Baskerville {Seicner, n. ser., 16 {1902), No. 397, p. 215). — An abstract of a paper 

 read before the North Carolina Section of the American Chemical Society at Raleigh 

 May 17, 1902, in which the author's experiments in fusing insoluble i^hosphates with 

 alkaline sulphates, sulphids, nitrates, and carbonates are briefiy referred to. 



The detection of nitric acid in presence of an alkaline ferrocyanid or 

 ferricyanid, A. F. Leuba {Ann. Ch'nn. Analyt., 7 {1902), No. 7, p. S58).—T\\q test 

 for nitric acid by adding sulphuric acid and a ferrous salt can not be made in the 

 usual manner in the presence of alkaline ferrocyanid s or ferricyanids, since these 

 form dark blue compounds. When, however, a slight excess of concentrated solution 

 of cadmium chlorid is added and the insoluble cadmium ferrocyanids and ferricyanids 

 removed by filtration the test may l)e made as usual. 



The determination of organic nitrogen in -water, H. Causse {Compt. Rend. 

 Acad. Sri. Pari^, 134 {1902) , No. 25, pp. 1520-1522; abs. in Chem. Centhl, 1902, II, No. 6, 

 p. 475). — In the method proposed the organic compounds of nitrogen are precipitated 

 by means of a saturated solution of baryta water containing 20 per cent of barium 

 chlorid, the organic matter destroyed by digestion in sulphuric acid, and the nitrogen 

 determined by nesslerizing the ammonia obtained by distilling the solution obtained, 

 after addition of an excess of potash. 



New apparatus in water analysis, A. (i. Woodman {Jovr. Amer. Chcm. Soc, 

 24 {1903), Nit. 9, pp. S"j7, S9S). — A criticism of the apparatus of Thomas and Hall for 

 collecting samples oi wati'r for the determination of dissolved oxygen or carbon 

 dioxid (Fv. S. R., 14, p. 10). The author explains why, in his opinion, the samples 

 collected in the way iiroposed do not represent the exact charactci' of the water l)eing 

 tested. 



Gluten feeds, determination of fat and acidity, E. (iudeman {Science, n. ser., 

 16 {1902), No. 399, p. 287).—T\\(^. autlior states that drying corn gluten feeds in hydro- 

 gen, vacuum, or air modifies them sufficiently to give low results for the percentage 

 of fat and increases the acidity of the extracted fat. (Tluten meals containing 5.16 

 per cent of fat before drying gave 3.56 after drying. The acidity of the fat extracted 

 before drying was from 5 to 15 per cent and after drying from 20 to 40 per cent. The 

 acidity as determined varies materially, according to the indicators used. The 

 author claims that acidity of feeding stuffs is due to the presence of acid salts, and is 

 no criterion of the quality of the feed or raw materials from which it was made. 



Glucose determination, E. Gudeman {Science, n. ser., 16 {1902), No. 399, p. 

 )■ — The author states that the polariscope gives incorrect results, due to the varia 



« School of Mines Quarterly, 22, p. 391. 

 ''Chem. News, 82, p. 101; 83, p. 37. 



