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times colourless oil, of a strong, but not disagreeable odour. It is so 
highly inflammable, that it catches fire, even on the approach of flame ; 
burning freely, with a large white flame, and leaving scarcely any 
residuum. Its specific gravity may be taken at .84/5 from Brisson. 
It does not freeze at 0°. Fahrenheit. It is insoluble in alcohol. By 
exposure to the air, it becomes yellow, and then brown ; and at the 
same time acquires a greater degree of consistency ; passing into 
petroleum. It is found in great abundance in Persia ; it sometimes 
is found on the surface of the waters of springs, and sometimes 
issuing from certain strata. 
Petroleum is a tenacious, brown fluid, which, according to the 
length of its exposure to the air, increases in thickness, and in dark- 
ness of colour ; until it acquires nearly the viscidity of common tar : 
its smell, at the same time, becoming less pleasant. In this state, 
although highly inflammable, it burns, with a flame less clear and 
white, yielding a soot, and leaving a small quantity of coaly re- 
siduum. Specific gravity, .8783, Brisson. It is also found in Persia, 
and likewise in many parts of Europe. 
Mountain or Mineral Tar is the name given to this sub- 
stance, when it has acquired the consistency and colour of common 
tar. It emits a strong bituminous smell, on being burnt. Specific 
gravity, 1. 1. 
Mineral Pitch and Maltha, are terms employed to mark 
the different higher degrees of colour and consistency, which this 
substance possesses in its further inspissation. Whilst so soft as to 
possess some degree of tenacity, it is called mineral pitch j but when 
it has become almost black, and so hard as neither to stain nor 
adhere to the fingers, it is termed maltha. Its specific gravity varies 
with its degrees of induration, and with the quantity of earth it 
contains. 
Asphaltum appears to be the same substance, in its highest 
degree of induration. It is a light, brittle, brown, or blackish sub- 
