246 On the Property/ ascribed to Quicklime 



The halt" of the four pounds which had beejn exposed 

 to moisture was also mixed with the same quantity of 

 quicklime. 



Our intention in regard to these different preparations of 

 gunpowder was to ascertain whether the presence of quick-» 

 lime added to its strength' either as a fourth component 

 part, and by a chemical action, or as an absorbent, by 

 taking from the powder the humidity it might contain, 

 which appeared to us much more probable. This we 

 hoped to discover, on the one hand, by the comparative 

 employment of the dry and pure powder, and of the dry 

 powder mixed with quicklime : on the other, by the pure 

 damp powder, and the same powder mixed with quick- 

 lime. 



We used for our experiments an old brass mortar which 

 had formerly served for tiying common gunpowder. It was 

 y inches 6 points in diameter, and had a cylindrjc chamber 

 the charge of which was three ounces, and the globe 60 

 pounds. 



The charges were weighed with the greatest exactness: 

 the mortar, being pointed at an elevation of 45 degrees, was 

 directed each time with such regularity that it deviated very 

 little from the line of firing. The mean ranges given at 

 each time of firing were as follows : 



Toises. Feet. 

 Dry and pure g:-; powder - _ _ i23 2 



Dry powder mixed with quicklime - 115 1 



Difference 



Pure damp powder r - - - 

 Damp powder mixed with quicklime 



Difference 



Not contented with these trials, we were desirous of re- 

 peating those 1 had made, eighteen monihs before, with 

 Regnier's spring proof; and every thing was arranged for 

 that purpose ; when, on the tirst discharge with fine hunting 

 gunpowder, or that frofii one of our powder manufactories, 

 the sprin"; broke, and consequently rendered the proof un- 

 serviceable. This accident, which took place when the 

 spring was compressed to the 28th degree, as announced by 

 the index, gives reason to suppose that it would have been 



much 



