Ammoniacal salts have been used in the manufacture of explosives to render them proof against firedamp, but not with the full-success desired. Ammonium chloride has been utilized, but inconveniences are met with, and the vapor is quite disagreeable. In cooperation with equivalent quantities of soda and potash, its action is regarded as favorable Tests employing benzine vapor and coal dust were made, and the comparative security calculated to be as given below.

I

Donarite, composed as follows: 80 per cent of nitrate of ammonia, 12 of trinitrotoluol, 4 of flour, 3.8 of nitroglycerine, and 0.2 per cent of cotton collodion. Security: Donarite alone, 87 parts; 95 per cent of donarite and 5 per

cent of ammonium chloride, 125 parts; 90 per cent of donarite and 10 per cent of ammonium chloride, 250 parts; 86 per cent of donarite and 5.5 per cent of ammonium chloride, with 8.5 per cent of nitrate of soda, 425 parts. The force of the explosion is decreased about 8 per cent, while the security is quintupled.

II

Roburite, with the following composition: 72.5 per cent nitrate of ammonia; 12 binitro-benzol; 10 nitrate of potash; 5 sulphate of ammonia; 0.5 per cent permanganate of potash. Security: Roburite only, 325 parts; ammonium chloride, taking the place of sulphate of ammonia, 400 parts. Here an intensification of the explosive force is simultaneously produced.

III

Amnion carbonite I, composed thus: 4 per cent nitro-glycerine; 75.5 nitrate of ammonia; 9.5 nitrate of potash; 9.5 coal dust; 10.5 flour. Security: Amnion carbonite I only, 250 parts; 95 per cent A. C. I. and 5 per cent ammonium chloride, 400 parts; 92 per cent A. C. I. and 8 per cent ammonium chloride, 500 parts. The addition of 5 per cent ammonium chloride diminishes the explosive force only 3 per cent.

IV

An explosive of nitro-glycerine base composed thus: 30 per cent nitroglycerine; 1 per cent cotton collodion; 52.6 nitrate of ammonia; 13 nitrate of potash; 3 to 4 per cent starch. Security of this mixture, 150 parts.

V

Thirty per cent nitro-glycerine; 1 per cent cotton collodion; 47.3 nitrate of ammonia; 11.6 nitrate of potash; 3.1 starch; 7 per cent ammonium chloride. This mixture has a security of 350 parts.