162 Fossils* 



cid of ants,the prussic acid, viz. the colou- 

 ring matter of prussian blue, which is ob- 

 tained from dried blood, hoofs, &c.the se~ 

 bacic or acid of fat, the bombic or acid of 

 silk- worms, the laccic or the acid of waxy 

 matter, and the zoonic, or the acid extrac- 

 ted from animal matter by means of lime. 



For a more full account of these acids 

 we refer the reader to various recent pub- 

 lications, written professedly on the sub- 

 ject of chemistry. 



Acids and alkalies, shew strong attrac- 

 tions for each other, and when combined 

 together in such proportion that neither of 

 them predominates, form neutral salts : 

 substances altogether dissimilar to the 

 elements of which they are composed. 

 The salt in common use for instance, is 

 formed of mineral acid and alkali ; either 

 of which, singly, would be hurtful to the 

 human body ; and the acid, in particular, 

 would be extremely pernicious. 



Each acid produces with each of the 

 three alkalies a particular neutral salt. 

 The number of the last may therefore 

 be found by multiplying the number of 

 the acids which we know, by three^ the 

 number of the alkalies* 



