iS 



2 



ILLUSTRATIONS OF THE 



d readlon between them, and the lighi; which 



they 



'/ whofe parts are kept frovifi 



filing away, not only by their fixity, hut alfo hy the 

 "vajl weight and denfdy of the atmofpheres incim^ 

 hent upon them, and very Jlron'gly comprejfmp 



7 



tbem 



* '> 



> 



163. The fad, of water boiling at a lower 

 temperature under a iefs compreffion, is fuffi- 

 cient to juflify the fuppdlition, that bodies may 

 be made by jiteiTure to endure e^Ltreme heat, 

 Tvithout the diffipation of their parts, that is, 

 ■without evaporation or combuftion. A further 

 poftidatum is introduced in Dr Hutton's theory, 

 namely, that compound bodies, fuch as carbo- 



nat of lime, when the compreffion prevents 

 their feparation, m/ay admit of fufion, notwith- 

 llanding that the fixed part may be infulible 



when feparated from the volatile. This affump- 



tion is fupported by the analogical fad of the 

 fufion of the carbonat of barytes, as mentioned 

 in the text. 



164. In a region where the adion of heat was 



panied with fuch compreffion as is 



he 



fuppofed, there could be no fire, properly fo 



called, and no combuft 



th 



mitted by 



DrPI 



-1 



d it is therefore a fall 



ar- 



gument which is brought againft his theory, 



from the impoliibility of fire being maintaii^ed 



in 



* Newton's Optics, Query 11 



