[ S3 ] 



il combined with calcareous earth, or any alkali, 

 in the form of an hepar fulphuris, it readily 

 diflolves - y in which cafe the water fmells difagree- 

 ably, like the fcourings of a gun, or putrid eggs* 

 It is diftinguifhed alio by a folution of faccha- 

 rum faturni (fugar of lead) in the nitrous or 

 vegetable acids •, a little of this folution being 

 marked in lines on paper* and the paper fuf- 

 pended over the water, the volatile fulphureous 

 fumes arifing from the water turn thefe lines of " 

 a brown or dark color the inflammable matter 

 of the fulphur uniting with the lead in the folu- 

 tion of the faccharum faturni, partly revives the 

 metal* and hence produces that dark color. 

 (See Seel. V; page 39, 40.) 



V. BITUMINOUS BODIES. 



Bitumen frequently runs from amongft rocks, 

 whence it is called petroleum ; it is alfo common 

 in the bowels of the earth* as hath been often 

 fatally experienced from thofe bituminous va- 

 pours called fire-damps, which prove inflam- 

 mable, and therefore differ from mephitic air, 

 the latter extinguifhing fire. Whether this in- 

 flammable vapour is formed of the principle of 

 inflammability of fulphur and the vitriolic acid 

 in a volatile ftate, is not fo well afcertained as 

 the remarkable effects produced by thefe bitu- 

 minous bodies in the mountains of iEtna, Vefu- 

 vius, and many others mentioned in hiflory. 



Liquid bitumen, naphtha, or petroleum, 

 is nev^r found combined with water, but floats 

 on its furface in a manner evident to the eye, 

 and may be particularly diftinguifhed by the tafte 

 and frneil, 



D VI. ME- 



