136 Dr. Ure on Gunpowders 



the dense sulphurous acid will be generated, and the less for- 

 cibly explosive will be the gunpowder. This is sufficiently 

 confirmed by the trials at Essonne, where the gunpowder that 

 contained twelve of sulphur and twelve of charcoal in one hun- 

 dred parts, did not throw the proof-shell so far as that which 

 contained only nine of sulphur and 15 of charcoal. The con- 

 servative property is, however, so capital, especially for the 

 supply of our remote colonies and for humid climates, that it 

 justifies a slight sacrifice of strength, which at any rate may be 

 compensated by a small addition of charge. 



Table of Composition of different Gunpowders. 



Nitre. Charcoal. Sulphur. 



Royal Mills at Waltham Abbey 75 15 10 



France, national establishment . 75 12. 5 12. 5 



French, for sportsmen . 78 12 10 



for mining ... 65 15 20 



United States of America . 75 12. 5 12. 5 



Prussia ..... 75 12. 5 12. 5 



Russia 73.78 13.59 12.63 



Austria . . . 76 11. 5 12. 5 



Spain . . . 76.47 10.78 12.75 



Switzerland, (a round powder) , 76 14 10 



Chinese .... 75 14. 4 9. 9 



Theoretical proportions (as above) 75 13.23 11.77 



6. On the Chemical Examination of Gunpowders. 



I have treated five different samples ; i. The Government 

 powder made at Waltham Abbey ; ii. Glass gunpowder made 

 by John Hall, Dartford ; iii. The treble strong gunpowder of 

 Charles Lawrence and Son ; iv. The Dartford gunpowder of 

 Pigou and Wilks; v. Superfine treble strong sporting gun- 

 powder of Curtis and Harvey. The first is coarse-grained, 

 the others are all of considerable fineness. The specific gravity 

 of each was taken in oil of turpentine : that of the first and last 

 three was exactly the same, being 1.80; that of the second 

 was 1.793, reduced to water as unity. 



The above density for specimen first, may be calculated thus: 



75 parts of nitre, specific gravity = 2.000 

 15 parts of charcoal, specific gr. = 1.154 

 10 parts of sulphur, specific gr. = 2.000 



