33* JLhmtnis of Mineralogy. 



foap, and two parts of mineral alkali, pouring 

 it when in fufion into a hot iron cone, or by 

 mixing it with oil to the confidence of a 

 fyrup, and then with a gradual heat diftilling 

 the whole to drynefs ; towards the end the 

 regulus fublimes, and may be made more 

 perfect by a fecond diftillation with its 

 own weight of oil ; by reafon of the offenfive 

 fmell the diftillation ihould be m^de in the 

 open air. 



CHAP, XII, 



Bifmuth. 



1. Bifmuth is of a reddifh or yellowifh 

 white colour, of a lamellar texture mode- 

 rately hard, and brittle ; its fpecific gravity 

 exceeds that of any of the femi-metals, or 

 even moft of the intire metals, yielding only 

 to that of platina, gold, jnercury, lead and 

 filver, being from 9,600 to 9,700 ; its fufi- 

 bility is nearly as that of lead \ \\ is eafily 

 foluble in nitrous acid or aqua regia, but 

 fcarcely in the vitriolic, and ftill lefs in the 

 marine ; its folution is colourlefs, and is pre-s 

 cipitableby the addition of pure water. 



2. 113 grains of this precipitate from 

 nitrous acid, well walhed and dried, areequi- 



t to 100 of bifmuth in its metallic forip. 



SPECIES. I. 



