162 Of the Sulphur 



* down to the bottom of the pot, the fulphur gra- 

 c dually confumes, and we can procure but little 

 4 or nothing of the acid fait of the fulphur. 



4 You muft be careful to clear the upper furface 

 c of the burning fulphur with an iron wire, or rod, 

 6 as there fettles on the top an earthy fkin, which 



* not only of itfelf gives no flame, but alfo quite 

 c fitiothers what does -, this only holds good of that 



* fulphur which is whitifh, blackifh, or of a green- 

 c ifti call:, a beautiful yellowifh fulphur being fub- 



•' jedt to no fuch accident 9 . 



Here M. Homberg takes notice of a difference 

 between fulphurs, as they happen to be crude and 

 purified, the latter of which muft be always 

 of a beautiful citron-yellow, the former being ge- 

 nerally of a greenifh caft, and fometimes inclin- 

 ing to an orange colour, from its containing fome- 

 thing foreign, particularly arfenic, which belongs 

 not at all to the nature of the fulphur ', and is fepa- 

 rable in the refining. 



c Though this procefs affords more of the acid 

 c fpirit of fulphur than the common method by 

 c the bell, yet ftill much of it is loft, as may be 

 c eafily perceived by the ftrong fulphureous fmell 

 c about the veffels ; fo that hence we cannot learn 

 c what is its due quantity and proportion in the 

 * fulphur. 



c This acid fpirit is entirely feparated from its 

 c inflammable fattinefs, and highly adapted to 

 c become a volatile, and almoft infipid fait, like 

 8 the acid fpirit of vitriol it{t\f 9 which it greatly 

 ' reiembles, nay, I might fay, is one and the 

 1 fame with.' 



What 



