[ II 1 



fufion, they ftiU would be far from refembllng thofe we are 

 acquainted with, which efTentially contain fome particles of 

 water, as I have elfewhere fliewn. 



Pkrhaps fome may fay that the fame difficulties occur in 

 accounting for the cryftallization of granite in the moift way; 

 on mature confideration however It will readily be feen, that 

 the caufes of coadunition in the dry and the moift way are very 

 dlflferent, and that their effeds fhould alfo be different. For 

 fuppofmg the earths, that enter into die eompofition of granites, 

 difTolved. in the moift way, their precipitation and imperfed 

 cryftallization may be afcribed to the union they contrad with 

 each other forming maffes ot each of the conaituent ingredients 

 of granite, which water can no longer hold fu^'pended -, hence 

 the precipitation of each of the three fpecies of ftone is nearly 

 contemporaneous, whereas if the formation of thefe ingredients 

 ftiould take place in the dry way, it would ncceffarily hzfuccejive, 

 keeping pace with the fucceffve diminutions of heat, and then 

 the abovementioned confequences would naturally enfue. 



The ftate of the granitic ingredients- in fufion which I have 

 above given agrees pretty nearly with that prefented by Sir 

 James himfelf ; he fuppofes the quartz, felfpar, fhorl, mica, 

 garnet, &c: melted together, and the moft fufible of them to 

 be the menftruum in v hich the reft are diffolved, and that they 

 differ from each other in theii: properties of fokition as falts 



B 2 'ii^'^- 



