149 
Fourcroy states, that there is obtained, from brown petroleum, 
by distillation, an acid phlegm ; and an oil which at first resembles 
naphtha, but which becomes coloured as the distillation proceeds. 
There remains in the retort, a thick matter, like maltha, and which 
may, by further exsiccation, be rendered dry and brittle, like as- 
phaltum; and, by a greater or longer continued heat, may be 
reduced to a charcoal. 
The alkalies have but little action on petroleum. The sulphuric 
acid darkens, thickens, and inflames it ; the same as it does the vo- 
latile oils. Petroleum readily dissolves sulphur ; it becomes coloured 
by the metallic oxides, and unites with amber, which it softens, and 
in part, dissolves, by the aid of heat. 
Fourcroy obtained from asphaltum, by distillation, an acid phlegm 
and a coloured oil, like petroleum. By fusion, he found asphaltum 
united intimately with sulphur, phosphorus, the fixed and volatile 
oils, resins, gum-resins, and many of the metallic oxides. Alcohol 
appeared not to touch it at all ; and ether had an evident, but a 
feeble action upon it*. 
Yours, &c. 
* Systeme des Connoissances Chymiques, tom. viii. p. 238. 
