126 Dr Gregory on the Composition of 



turpentine of the great pine-forests, to which our coal-beds owe 

 their origin, having been separated by a gentle heat, either before 

 the conversion of the wood into coal, or from the coal itself, as in 

 his own experiments. It does not appear distinctly what native 

 naphtha Dr Reichenbach examined ; but, from several passages, 

 it would seem to have been that of Amiano. 



On reading the last mentioned memoir of Reichenbach, it 

 seemed obvious that the character given by him of this naphtha 

 was very different from that of Persian naphtha, or from that of 

 the naphtha which may be obtained from the petroleum of Ran- 

 goon by distillation ; and when, in addition to this, we consider 

 the existence of paraffine in the latter, it is impossible not to in- 

 fer, that, if Dr Reichenbach's experiments be correct, or rather 

 if his naphtha were genuine, there must exist, at least, two very 

 different kinds of naphtha. T resolved, therefore, to subject the 

 Rangoon oil to a new examination, in order to ascertain whether 

 or not it contained eupione. Dr Christison having kindly sup- 

 plied me with a considerable quantity, I proceeded to rectify it, 

 in the first instance ; and I very soon obtained a liquid, possessed, 

 in a very considerable degree, of the properties of eupione, parti- 

 cularly its mobility, low sp. gr., and odour like that of narcissus. 

 This rectified naphtha, although far from pure, has a sp. gr. of 

 only .765, and boils at 200° F. I then subjected it to the action 

 of oil of vitriol, and of a concentrated solution of potash, several 

 times alternately, and also, as recommended by Reichenbach, 

 to distillation with strong sulphuric acid and nitre. It resisted 

 all these agents, for the most part, and, when finally rectified, 

 assumed the appearance of the specimen No. 2., the sp. gr. of 

 which is .744, which boils at 180° F., and which possesses, in a 

 more marked degree than before, the peculiar odour of eupione. 

 This odour, I may add, is exactly that of some impure eupione, 

 which I extracted from coal-tar naphtha, and from the liquid 

 produced by distilling caoutchouc. The smallness of the quan- 



