122 Professor Christison on the Petroleum of Rangoon. 



limate. When heated in the open air, it catches fire, and burn^ 

 with a dense white flame and much black smoke. 



Petroline is insoluble in water, cold or boiling. Boiling al- 

 cohol takes up a small quantity, not more than a 450th of its 

 weight, and on cooling deposites the greater part in minute shin- 

 ing crystals. Boiling ether, its proper solvent, easily takes up a 

 fifth of its weight, which on cooling is in a great measure sepa- 

 rated in a congeries of micaceous crystals, so abundant as appa- 

 rently to convert the ether into a solid mass. Oil of turpentine 

 also dissolves it in large quantity, and so does naphtha. 



Caustic potass and caustic ammonia in solution have no visi- 

 ble effect on this substance. When boiled with it, it simply 

 fuses, rises to the surface, and is there found, on cooling, with its 

 usual properties. Concentrated muriatic, nitric, and sulphuric 

 acids are equally without action, even when aided by the heat 

 necessary to boil each. It simply melts and rises to the surface, 

 and, except that it becomes slightly yellow with nitric, and slight- 

 ly brown with sulphuric acid, no change of property is percepti- 

 ble. It has no action with acetic or oxalic acid. 



With iodine aided by a gentle heat, it quickly unites, form- 

 ing a violet-coloured fluid, which on cooling becomes a dirty 

 greenish-brown solid, very soluble, like each of its elements, in 

 sulphuric ether. 



I have not made any inquiry into the other chemical rela- 

 tions of petroline, my object at present being merely to establish 

 its claims to be considered a new principle, distinct from any 

 other hitherto known. In its properties it resembles naphtaline 

 more than any other substance ; but at the same time it differs 

 from that body in very many respects. Naphtaline volatilizes at 

 common atmospherical temperatures ; does not fuse under 1 80° 

 Fahr. ; and, when heated a little above 400°, boils and sublimes 

 in fine micaceous crystals. It is heavier than water. It forms 

 a rose-coloured solution with acetic or oxalic acid ; and with sul- 

 phuric acid it unites to form a peculiar acid, termed the Sulpho- 



