the Petroleum of Rangoon. 129 



amined by Dr Reichenbach, the only substance present ; and if 

 the characters I have mentioned be sufficient to prove the pre- 

 sence of eupione, these oils must be considered products of de- 

 structive distillation. This point, as far as the Rangoon naphtha 

 is concerned, has, I think, been decided by the discovery of pa- 

 raffine in it ; and I think I have been able to ascertain the same 

 fact with regard to the Persian naphtha described by Dr Thom- 

 son. Dr Thomson sent me two specimens, one of Persian 

 naphtha, which Mr Swinton considers genuine ; the other of pe- 

 troleum, which Dr Thomson said would yield the same naphtha. 

 The latter, however, turns out to be Trinidad asphaltum sent by 

 mistake. My experiments, therefore, were confined to the naph- 

 tha already mentioned. This naphtha, being the most volatile 

 portion of the petroleum, cannot be expected to contain more 

 than a trace of the paraffine, which accumulates on the more fix- 

 ed portions. Accordingly, on redistilling this naphtha, and col- 

 lecting separately the last portion distilled, I found that when 

 exposed to cold it became semisolid, just like the latter portions 

 of the distillation of the Rangoon petroleum. I shall take the 

 first opportunity of deciding the question on a larger scale ; but 

 in the mean time, from the great resemblance between this Per- 

 sian naphtha and that of Rangoon, and the indications of paraf- 

 fine I have obtained from the former, I am inclined to believe 

 that the Persian and Rangoon petrolea are identical in composi- 

 tion. 



In conclusion, I would beg to state the chief results which 

 I have endeavoured to establish. 



1 . That there are some kinds of naphtha which contain pa- 

 raffine and eupione, and are consequently the results of destruc- 

 tive distillation. 



2. That the naphtha examined by Dr Reichenbach, which 

 was oil of turpentine, if genuine, differs materially from that of 

 Rangoon and of Persia, as well as that now sold in Paris, which 

 are decidedly not oil of turpentine. 



VOL. XIII. PART i. R 



