Note 131 — RESEARCH I. (continued 2)
Reading edition
Humbolt, who is the first philosopher that has applied the solution of sulphate of iron to ascertain the purity of nitrous gas, asserts that he uniformly found nitrous gas obtained from solution of copper in nitrous acid, to contain from six tenths to one tenth nitrogene.
Annales de Chimie, vol. xxviii. pag. 147.