MINERALOGY. t$f 



periments, if their qualities had been re- 

 garded, in preference to their figures, 

 or their native places. 



This may be called Englifh or Epfom 

 fait, when it has naturally as equal a co- 

 pious portion of the calcareous earth as of 

 the artificial one ; but I have, in regard 

 to its effects, for which it has been moll 

 valued by Glauber, ranked all the lefs 

 confiderable varieties of this neutral fait, 

 when natural, under the name of fal mi- 

 rabile. 



SECT. CXXVII. 



B. Acid of common or fea-falt, Acidum falls 

 communis. 



This acid, confidered in that ftate in which 

 it can be had, viz. in mixture with water, 

 has the following qualities. 

 i . It does not alter the fluidity of water, nor 



confiderably augment its heavinefs, as the 



vitriolic acid does. 



2. It is fomewhat lefs corrofive and four than 

 the faid vitriolic acid. 



3. It flrongly attracts the alcaline falts; but, 

 however, is forced to quit them to the vi- 

 triolic acid, when that is added. 



4. It diffoives the calcareous earth, and makes 

 with it a fubflance, called fal ammoniacum 

 fixum. 



5. When expofed to the fire, combined with 

 a phlogifton, it burns with a yellowifh 

 green flame. 



6. When highly concentrated and pure, as 

 when it is diftilled from common fait mixed 

 with pipe clay, it difiblves Un and lead : 



but 



