ELASTIC BITUMEN. ASPHALT. 14?9 
repute has been obtained from its being thought useful 
in disorders of the breast and lungs, though this appli- 
cation of it is considered very improper. It is likewise 
used as ap external remedy in paralytic disorders. 
215. ELASTIC BITUMEN, or MINERAL CAOUT- 
CHOUC, has a strong resemblance to Indian rubber. In some 
instances it is elastic, and so soft as to adhere to the fingers, 
and in others brittle, and so hard as nearly to resemble as- 
phalt (216). 
Its 'Colour is yellowish, reddish brown, or blackish. One 
kind of this mineral, when fresh cut, nearly resembles fine 
cork, loth in texture and colour. 
This extraordinary substance, which will expunge the 
marks of black lead in the same manner as Indian rub- 
ber, was first discovered, about the year 1786, in cavi- 
ties of the lead mine of Odin, near Castleton, in Derby- 
shire, and it has not hitherto been found elsewhere. 
Elastic bitumen appears to be a peculiar modification 
of petroleum, in its passage to asphalt : and probably 
owes its elasticity to its cellular texture, and to the 
moisture with which it is combined. 
216. ASPHALT, or SOLID BITUMEN, is a brittle 
substance, of black or brownish black colour, and of consistence 
somewhat harder than pitch. 
It has nearly the same weight as water, is smooth to the 
touch, does not stain the fingers, and has little or no smell un- 
less it be rubbed or heated. When heated, it melts, swells and 
inflames ; and, if pure, burns without leaving any ashes. 
The ancients were well acquainted with this sub- 
stance, which is nothing more than mineral tar (214<yin 
an indurated or hardened state. It is found on the 
surface of volcanic productions, and floats, in solid 
pieces, and in considerable abundance, on the Asphaltic 
Lake, in Syria, which has thence received its name. 
This lake is also called the Dead Sea, from a notion 
that the odour arising from the asphalt destroys even 
birds which fly over it: Maundrell, however, states that 
this is not true, as he saw several birds fly about and 
over it, without experiencing the slightest injury. 
