upon Gun-powder , &c. 263 
fufficient to burn up all inflammable bodies that it came near, 
and to melt the (hot that it furrounded and impelled, efpecially 
when they werefmall, and were compofed of lead or any other 
foft metal ; but, on the contrary, we frequently fee the fin eft 
paper come out of the mouth of a piece uninflamed, after it 
has fuftained the adtion of the fire through the whole length of 
the bore, and the lmalieft lead {hot is difcharged without being 
melted. 
But it may be objected here, that bullets are always found to 
be very hot if they are taken up immediately after they come 
out of a gun ; and that this circumftance is a proof of the intern 
fityof the heat of the flame of powder, and of its great power 
of communicating heat to the denfeft bodies. But to this I 
anfwer, I have always obferved the fame thing of bullets dift 
charged from wind-guns and crofs^bows, efpecially when they 
have impinged againft any hard body, and are much flattened ; 
and bullets from mufkets are always found to be hotter in pro- 
portion to the hardnefs of the body againft which they are 
fired. If a mufket ball is fired into any very foft body, as (for 
inftance) into water, it will not be found to be fenfibly warmed ; 
but if it is fired againft a thick plate of iron, or any other body 
that it cannot penetrate, the bullet will be demolilhed by the 
blow, and the pieces of it that are difperfed about will he 
found to be in a ftate very little fhort of fufion, as I have often 
found by experience. It is not by the flame therefore that bul- 
lets are heated, but by percuftion. They may, indeed, receive 
fome fmall degree of warmth from the flame, and ftill more 
perhaps by fridtion againft the tides of the bore, but it is in link- 
ing againft hard bodies, and from the refiftance they meet with 
in penetrating thole that are fofter, that they acquire by far 
2 N z the 
