Chap. 51.] BITUMEN. 293 



also to be perceived in certain hot mineral waters f^ and there 

 is no substance that ignites more readily, a proof that there is 

 in it a great affinity to fire. Lightning and thunder are at- 

 tended with a strong smell of sulphur, and the light produced 

 by them is of a sulphureous complexion. 



CHAP. 51. J3ITUMEN, AND THE SEVEEAL VAKIETIES OF IT; 



TWENTY" SEVEN KEMEDIES. 



Nearly approaching to the nature of sulphur is that of bitu- 

 men/ which in some places assumes the form of a slime, and 

 in others that of an earth ; a slime, thrown up, as already''^ 

 stated, by a certain lake in Judsea, and an earth, found in the 

 vicinity of Sidon, a maritime town of Syria. In both these 

 states, it admits of being thickened and condensed. There 

 is also a liquid^ bitumen, that of Zacynthus, for example, and 

 the bitumen that is imported from Babylon ; which last kind 

 is also white : the bitumen, too, of Apollonia is liquid. All 

 these kinds, in Greek, have the one general name of *'pissas- 

 phaltos,""* from their strong resemblance to a compound of 

 pitch and bitumen. There is also found an unctuous liquid 

 bitumen, resembling oil, in a spring at Agrigentum, in Sicily, 

 the waters of which are tainted by it. The inhabitants of the 

 spot collect it on the panicles of reeds, to which it very readily 

 adheres, and make use of it for burning in lamps, as a sub- 

 stitute for oil, as also for the cure of itch- scab in beasts of 

 burden . 



Some authorities include among the bitumens, naphtha, a sub- 

 stance which we have already mentioned in the Second Book;* 

 but the burning properties which it possesses, and its sus- 

 ceptibility of igniting, render it quite unfit for use. Bitumen, 

 to be of good quality, should be extremely brilliant, heavj^ 

 and massive ; it should also be moderately smooth, it being- 

 very much the practice to adulterate it with pitch. Its medi- 



^ S^ee B. xxxi. c. 32. 



^ There are three distinct kinds of bitumen. 1. Naphtha, also known 

 as petroleum, or rock-oil, inflammable, volatile, soluble in alcohol, and 

 found in France and Italy. 2. Asphalt, or bitumen of Judaea, solid, in- 

 soluble in alcoliol, and found in Lake Asphaltites in Syria, more particu- 

 larly. 3. Pissasphalt, of a medium consistency between the other sub- 

 stances, of which it appears to be composed. See B. xxiv. c. 25. 



2 InB. V. c. 15 2 Naphtha, most probably. * See B. xxiv. c. 25. 



5 Chapter 109. 



