THE PRODUCTION OF EXPLOSIVES 135 



many other mathematicians and physicists discussed its effects 

 on projectiles ; granulation was introduced in 1445 ; Benvenuto 

 Cellini observed the necessity for adapting the grains to the gun, 

 and devised the system of blending; Hawksbee, in 1702, meas- 

 ured the volume of gas resulting from a known volume of 

 powder; Robins, and then Hutton, developed the ballistic pen- 

 dulum ; and Rumford measured the pressure produced by gun- 

 powder in burning, all prior to the nineteenth century. 



In connection with his duties in the office of the ferniier 

 general of France, Lavoisier was, in 1775, designated registeur 

 des poudres, when he at once proceeded to install a laboratory 

 at the Arsenal in Paris and to apply his chemical knowledge 

 to improvements in the production of saltpeter and in the 

 manufacture of gunpowder. Among his pupils was E. I. du 

 Pont de Nemours, who spent some time in the royal powder 

 mills at Essone, qualifying as a successor to Lavoisier as 

 superintendent and who, on July 19, 1802, on the advice of 

 Thomas Jefferson, began the gunpowder works on the Brandy- 

 wine at Wilmington, Delaware, which have been continued to 

 the present day. 



The creation of this laboratory by Lavoisier may properly 

 be taken as the beginning of precise chemical investigations of 

 explosives, and his example was followed by many other chem- 

 ists, among those investigating gunpowder being Berthollet, 

 Gay Lussac, Violette, Chevreul, Bunsen and Schischkoff, Linck, 

 Karoyli, Noble and Abel, Hare and Debus. 



Although picric acid had then been known and, to some ex- 

 tent, used as a bitter principle and coloring matter, and with 

 metal-amines, styled fulminating silver, gold and the like, had 

 been developed as interesting chemical material, the beginning 

 of modern explosives dates from the discovery of mercury ful- 

 minate by Howard in 1800, and from the middle of the nine- 

 teenth century on followed the discovery of the nitric esters 

 from starch, wood, cotton, glycerin, sugars and other alcohols, 

 known as nitro starch, nitro lignin, nitro cellulose, nitro gly- 

 cerin, and nitro sucrose ; of diazo-bodies, and of hydronitrides ; 



