OF FOSSILS. 313 



Compound falts, produced by rcgalinuin (a- 

 qua rcgis) never bccumc triple, at lead not all 

 of them. The nitrous acid fceins to be ncccila- 

 ry for the purpofeofdcphlogillication only; and 

 the muriatic generally exhibits the lame combi- 

 nations as the regulinc, by which, if the muria- 

 tic is not in fuii.cient quantity, a double fait is 

 obtained, charged with the nitrous acid, 



The fame observation is equally applicable to 

 the quadruple fails. 



rr , r. ' ^ Tartar united to bo- 



lartarum Fevri, < 



C rax 



Nitrofum Kunckclii, Rubini Kunckclii. 

 r . . C Sal ammoniac with 



Ompnthicum, -j n i tial cd coppcf. 



This fait exhibits cryflals, that alllnnc a yel- 

 low colour when heated, but become blue in a 

 moderate tempeiature. If a folution of them 

 fufticicntly diluted is ufed for writing, the let- 

 ters will be found to difappcar entirely, by the 

 application of heat ; and, if cxpofcd to the va- 

 pour of cauftic volatile alkali, to change to a 

 beautiful blue colour. 



Thus, then, 1 have pointed out a method, as 

 I apprehend, both eafy and fimple, by which all 

 the known falts, about fifty in number, may 

 be each denominated in one or at moil in two 

 words. According to the firfl diviiion, we have 

 the genus only. Of the fecund, the double falts 

 completely fa tn rated are indicated by the nd- 

 jcdivc of their bafe ending in atus. In the 

 third, the impcrfeft falts arc known by the 



genitive 



