Chap, 3.] yifrislic or Acid cf Sulphur. ir 



with much nwe pr-'>p-:eiy called the acid of fulphur, 

 ES it is now found -to be a (orr.bhation of that inflam- 

 mable fubftance with oxygen. The pungent and 

 iliffocating fumes which are produced by the inflam- 

 mation of fulphur, are an acid which is imperfect >from 

 a deficiency of oxvgen ; and which ( annot be con- 

 denfed without the aid of water. The vitriolic acid 

 can never be entirely deprived of water, but admits 

 of the greateft concentration of all the acids, and may 

 be reduced to a (b.te in which its fpecific gravity is 

 double that of water. The denfe and fluggifh ap- 

 pearance of the concentrated vitriolic acid has given 

 rife to the improper name of oil of vitriol, under which 

 it paffes in the fhops. 



M. Lavoifier makes a diftincYion between this acid, 

 as it exifts in an imperfect and gaffeous ftate, and as 

 it exifts in' the form of a tranfparent and ponderous 

 liquid combined with water. In its former ftate he 

 calls it, acidejulphureux (fulphureous acid) in the latter, 

 acide Jutyhurique. (fulphuric acid). A fimilar differ- 

 ence of termination is employed to exprefs the dif- 

 ferent ftates of the nitrous acid, according as it is 

 imperfectly or completely faturated with oxygen. A 

 difference of termination is alfo given to the combi- 

 nations of acids, according as they are perfectly or 

 imperfectly faturated with oxygen. Thus the com- 

 binations of the fulphureous acid, are called Julphites ; 

 thofe of the fulphuric acid,/#^>&/j, &c. 



The vitriolic acid now ufed in commerce is pre- 

 pared in the following manner : A quantity of ful- 

 phur and falt-'petre, grofsly mixed, are placed in a 

 vefTel within a fmall room, lined with lead, and con- 

 taining a few inches depth of water at bottom. The 

 fulphur is lighted, and the room doled. The falt- 

 petie ferves to maintain the combuftion, by the oxy- 

 genous 



