Dr Reichenbach on Petroleum or Mineral-oil. 



tine oil qftJie pirles of former ages ; not only the wood, but also 

 large accumulations of the needle-like leaves of the pines may 

 also have contributed in this process. We should thus have 

 the satisfaction of obtaining, after the lapse of thousands of years, 

 information as to the more intimate composition of those an- 

 cient destroyed structures of the period of the great coal forma- 

 tion, whose comparison with the vegetation of our globe is the 

 subject of so many investigations ; and we should thus be able to 

 rank the substance with the few which from a later period, viz. 

 that of the quadersandstone formation, have reached us in the 

 form of amber, and a iew other similar bodies. The appear- 

 ance, then, of petroleum in many of the scattered springs of the 

 earth does not depend on combustion, but is, as I believe, simply 

 the result of the action of subterranean heat. According to 

 the information we now possess,, it appears that it is not neces- 

 sary that strata should be very deep under the surface, in order 

 to be reached by a heat equal to the boiling point of water or 

 mineral-oil. In such a position the oil must have suffered a slow 

 kind of distillation, and under appropriate circumstances must 

 gradually have found its way to the surface, or must have im- 

 pregnated so completely a portion of the earth, as to enable us 

 to collect it from wells, as in various parts of Persia and India. 

 In my memoir on Eupion, in this Journal (for 1831, vol. ii. 

 ■ part 2), I have mentioned the possibility of the existence of 

 that substance in mineral-oil, although I could not succeed in 

 detecting any correspondence between these bodies or their com- 

 ponent parts. In that essay, I omitted mentioning many expe- 

 riments performed with that view. From the explanations af- 

 forded by the present investigation, it is now evident why my 

 efforts to identify these two substances proved unavailing ; sub- 

 stances which, according to the hitherto adopted opinion as to 

 mineral-oil, I regarded as of similar origin, or as formed from 

 dry distillation, whereas now an entirely different view as to 

 mineral oils presents itself. The Eupion is a product of dry 

 distillation ; whereas the mineral-oil is derived directly from the 

 action of vegetable life, and both substances, although they ex- 

 hibit external points of analogy, are yet widely different in their 

 nature and probably in composition. Indeed, one might, on the 

 contrary, rather look for mineral-oil in Eupion, when the tar 

 from which the Eupion has been obtained is coal-tar. For, in 



