Inflammables. 209 



SPECIES I. 



Inflammable Alr^ Fire Damp. 



This is eafily known by its property of 

 inflaming, when mixed with twice or thrice its 

 bulk of common atmofpheric air. When 

 pure, it explodes all at once, but when mixed 

 or combined with fixed air, it burns with a 

 blue lambent flame. It frequently occurs 

 in coal-pits and mines, and often on the fur- 

 face of fprings in Perfia, Italy > and France* 

 and feems to be nothing more than the ex- 

 halation of petrol. 



SPECIES II. 



-" 



Hepatic Air. 



This air feems to confift of fulphur, held 

 in folution in vitriolic or marine air ; it is in- 

 flammable when mixed with -| of its bulk of 

 common air. Water will take up about i 

 its bulk of this air, and when faturated with it 

 will turn filver black, but if ftrong dephlogifti- 

 cated nitrous acid be dropped into this water, 

 the fulphur will be precipitated. 



loo Cubic inches of this air, when united 

 to water, may hold 8 grains of fulphur in 



P jfolution, 



