94 
“ nitron ” as a readily available means for estimating* the quantity as 
well as detecting the presence of nitric acid and nitrates. — Ztschr. f. 
angew. Chem., 1905, v. 18, pp. 494-499. 
Busch, M., discusses the gravimetric estimation of nitric acid by 
means of “ nitron,” the diphenyl -endanilo-dihydro-triazole, the use 
and preparation of which is described. (Ber. 1905, v. 38, pp. 856- 
860.) Nitron is said to be efficient for the detection of nitric acid, 
free or combined ; 1 : 60000 at ordinary temperature, 1 : 80000 at 0° C. 
Also for the determination of nitric acid and for the detection as 
well as the determination of nitrate in the presence of nitrites. — 
Abstr. J. Soc. Chem. Ind., Lond., v. 24, 1905, p. 292. 
Pfyl, B., proposes a simple method for the estimation of nitric 
acid in the presence of organic substances. This consists in the re- 
duction of the nitric acid to nitric oxide by means of ferrous chloride 
and hydrochloric acid, washing the gas with 15 per cent solution of 
sodium hydrate in the absence of air and passing the resulting 
washed gas into a 1/10 N. permanganate solution to absorb the nitric 
oxide. The excess of permanganate solution is then titrated back 
with ferrous oxide. — Ztschr. f. Unters. d. Nahr. u. Genussm., Berlin, 
1905, v. 10, p. 101. 
Meisenheimer and Heim discuss the determination of nitric acid 
and nitrous acid. — Biochem. Centralbl., 1905-6, v. 4, p. 567. 
Frerichs, G., calls attention to the fact that diphenylamin is not 
always directly applicable for the demonstration of nitric acid in 
solutions, and advises the washing out of the nitric acid with ether 
and the use of this ethereal solution for the test with diphenylamin. 
As sulphuric acid reacts violently with ether, the diphenylamin 
solution should be added carefully drop by drop. (From Arch. d. 
Pharm., 1905.) — Abstr. Pharm. Zentralh., 1905, v. 46, p. 947. 
Burke, W. J., examined 25 samples of dilute nitric acid ; 2 were of 
the U. S. P. strength, 10 below, and 13 above; ranging from 7.5 to 
17.9 per cent of HNO s . — Proc. Massachusetts Pharm. Ass., 1905, 
p. 105. 
Hall and Cooper consider the effects of the inhalation of the fumes 
of nitric acid. — J. Am. M. Ass., Chicago, 1905, v. 45, p. 396. 
ACIDUM PHOSPHORICUM. 
Herting, Otto, discusses the composition and tests for phosphoric 
acid. — Deut.-Amer. Apoth. Ztg., N. Y., 1905, v. 26, p. 155. 
Patch, Edgar L., found samples of phosphoric acid that contained 
traces of iron and of silica ; one lot was mostly metaphosphoric 
acid. — Proc. Am. Pharm. Ass., 1905, v. 53, p. 182. 
Arnold and Werner (Chem. Ztg., 1905, v. 29, pp. 1326-1327) point 
out that the published reactions for phosphoric acid have been 
shown to be generally unreliable; they suggest a new series of tests 
