On a new fulminallng JMercury. 9,t 



the "breech, being fuddenlv enlarged, afted as a wedge upoa 

 the barrel. The ball mifll-d the block of wood and flruck 

 againft a uall, which iiad already bi.-e!i the receptacle of fo 

 many bullets, that we could not latisfy ourfelyes about tlie 

 impreffiou made by this laft. 



Section VI. 



As it was pretty plain that no gim could confine a quan- 

 tity of the mercurial powder fufficietit to project a bullet with 

 a greater force than an ordinary charge of gunpowder, I de- 

 termined to try its comparative ftrength in another way. 



I procured two blocks of wood, very nearly of the fame 

 fizc and ftrength, and bored them with the fame inftrument 

 to the fame depth. The one was charged with half an ounce 

 of the beft Dartford gunpowder, and the other with half an 

 ounce of the mercurial powder ; both were alike buried in 

 fand, and fired by a train communicating with the powders 

 by a fmall touch-hole. The block containing the gunpowder 

 was fimply fplit into three pieces ; that charged with the mer- 

 curial powder was burft in every direflion, and the parts im- 

 mediately contiguous to the powder were abfolutely pounded; 

 yet the whole hung together, whereas the block fplit by the 

 gunpowder had its parts fairly feparated. The fand fur- 

 rounding the gunpowder was undoubtedly moft difturbedr 

 in (hort, the mercurial powder appeared to have adltd with 

 the greateft energy, but only within certain limits. 



Section VII. 



The effefts of the mercurial powder, in the laft experi- 

 ments, made me believe that it might be confined, during its 

 cxplofion, in the centre of a hollow glafs globe. Having 

 therefore provided fuch a veflel, 7 inches in diameter, and 

 nearly half an inch thick, mounted with brafs caps, and a 

 ftop-cock, (fee Plate T.) I placed ten grains of the mer- 

 curial powder on very thin paper, laid an iron wire 149th of 

 an inch thick acrofs the paper, through the midft of the 

 powder, and, doling the paper, tied it faft at both extremi- 

 ties, with fdk, to the wire. As the inclofcd powder was now 

 attached to the middle of the wircj each end of which was 



connected 



