f io ] [BookVIl 



CHAP. III. 



ACIDS 



in general -Vitriolic ^cid ', ha-M obtained, &C. Nitrcu- 

 A.-id\ bcnu obtained* Muriatic Acid; bo~M obtained, and its U/e 

 in the Arts .Flucr Acid ; dijjolves Glafs ; employed to make 

 Etchings on Glojs 4<-id of Borax Pkojf boric Add.^Acid of 



ACIDS are very active fubftanc.es, and when 

 concentrated arc highly corrofive, They have 

 (b general a. tendency to unite with other fubftances,, 

 that they are never obtained pure except by art. 

 They are generally fluid, which feems, however, 

 chiefly to be owing to their ffcrong attraction for water, 

 ot which few of them can be entirely .deprived, and 

 \vhich they copioufly attract from the atmofphere. 

 One ^ f the marks by which the prefence of uncom- 

 bined acids may be afcertained, is their property of 

 changing to a red, the blue colour of infufion of 

 vipkts, which alkalis change -to a green. Acids are 

 diftinguifhed into mineral, vegetable, and animal j the 

 -fubjecl of this book will at prefent confine us to thofe 

 'of the firft clafs. 



The acids found in the mineral kingdom are the 

 carbonic acid or fixed air, the vitriolic, the nitrous, the 

 mu;iatic, the acid of fpar, the acid of borax, the acid 

 of phofphorus, and the acid of amber. 



The CARBONIC acid has already been treated of 

 under the head of gafles. 



The VITRIOLIC acid takes its name from vitriol 

 or copperas, from which it was formerly extracted by 

 diftillation. In the new chemical nomenclature, it is 



with 



