HISTORT of the SOCIElT. i-j 



Phyf. CI. Mr Stewart read a paper by Dr Hutton, viz. An 1796. 



Examination of a New Phenomenon which occurs in the fulphu- ^^ „ Y ^' 



X XJT rlutton on 



rating of Metals, with an Attempt to explain that Phenomenon. tLVof^roetaL. 



An account that was given, fome time ago, in the Literary 

 Journals, of certain experiments made in Holland on the ful- 

 phurating of metals, gave rife to this communication. Accord- 

 ing to that account, when metallic filings are mixed with ful- 

 phur, and expofed in a clofe vefTel to a certain degree of heat, 

 the mafs kindles, and burns not only without vital air, but in 

 any air whatfoever, or even in a vacuum. In the experiment, 

 as thus reprefented, Dr Hutton readily faw a ftrong argument 

 againft the theory which explains the phenomena of fire by the 

 extrication of the calorique of vital air ; and in this light he con- 

 fidered it in the end of the DifTertation on the Philofophy of Light, 

 &c. of which an abftra(5t has been already given. Dr Hope ha- 

 ving however fuggefted to him, that, in making the experiment, he 

 had feen reafon to doubt the reality of the inflammation, they 

 agreed to repeat the experiments together. Dr Hutton was then 

 convinced that this fadl had been mifreprefented, or rather mif- 

 underflood ; and therefore thought it neceflTary, in this paper, 

 to corre6l the error into which he had been led by that mifre- 

 prefentation, defcribing the real appearances, and endeavouring 

 to explain them on known principles. " In doing this," fays he, 

 " I fhall deftroy the argument which the experiment feemed to 

 afford againft the docftrine of calorique, but I fliall have no rea- 

 fon to change the conclufion that I formed againft that doc- 

 trine, founded on fadls that are univerfally acknowledged." 



The fadl, as thefe gentleman obferved it, is this : The metal 

 and fulphur being mixed in due proportions, and expofed to heat 

 in a clofe glafs veflel, the fulphur firft melts, then undergoes a 

 kind of ebullition, emitting vapours which condenfe in the up- 

 per part of the veflel, and are a fublimation of the fulphur. ' In 



d 2 thi& 



