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learn, that it is so inflammable, that it takes flame before the 

 flame which is brought towards it is really in contact with it ; that, 

 when heated in a vessel, it inflames by the flame of a candle held at 

 a considerable distance above it, a subtile vapour extending some 

 feet above the fluid ; and that it will burn freely on the surface of 

 water. He also states, that it is so light as to swim on the surface 

 of all fluids, even on that of rectified spirits of wine, which is 

 heavier than it by one-seventh, and does not manifest any action on 

 it. One drop diffused itself over water to more than the space of 

 a toise, the water yielding prismatic colours. It mixed perfectly 

 with the essential oils, particularly with the oils of turpentine, of 

 thyme, and of lavender. He observed also, that it did not inflame 

 on the addition of the concentrated acids, but became thickened 

 on their union with them. A piece of paper soaked with it, soon 

 became dry, and then, as is the case when spirit of turpentine is 

 used, ceased to be transparent. 



By distillation with a gentle heat, du Ble *, obtained from the as- 

 phaltum of Neuenberg, a light and limpid oil, which, like naph- 

 tha, was so subtile, as to evaporate very rapidly in the open air ; 

 spreading very freely on the surface of water, and taking flame 

 Very readily. But unlike naphtha, which, according to Boulduc, 

 will not unite with alcohol, this essential oil entered into union 

 with alcohol with the same facility as oils of lavender and tur- 

 pentine. 



By properly adapted experiments, he also ascertained, that in 

 the asphaltum of Neuenberg, both the sulphuric and muriatic acids 

 existed, in union with calcareous earth. 



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. 



* C. Ludov. 1'Agascherie clu Ble, Examen Bitwninis Neocomejisis, 1758. 



