the Petroleum of Rangoon. 127 
tity has alone prevented me from pushing the purification 
further. 
From these experiments, I consider myself entitled to con- 
clude, that the petroleum of Rangoon contains eupione in very 
considerable quantity ; and, as Dr Curtstrson has already shewn 
that paraffine may be extracted from it, we can no longer doubt 
that it has been produced at a high temperature, or, in other 
words, that it is a product of destructive distillation. 
Dr Crristisoy, in his original paper on petroline, mentioned 
that a quantity of oil, sent by Mr Swinton to the Society as 
pure Persian naphtha, appeared to be pure oil of turpentine, 
which he concluded to have been substituted for the naphtha. I 
at first thought from Dr Rercuensacn’s experiments, that it 
might have been at once genuine naphtha, and genuine oil of tur- 
pentine ; only, in this case, it must have been of that species’ of 
naphtha, which, like the artificial naphtha distilled from coal at 
212° by Retcrennacn, is not the product of destructive distilla- 
tion. But Mr Swinton states that it has not the characters of 
true Persian naphtha, and although he was persuaded at the 
time that he had sent genuine naphtha, he is now convinced that 
a mistake has been committed. The Persian naphtha described 
and analyzed by Dr THomson some years ago, of which he was 
kind enough to send me a small specimen, has again the charac- 
teristic odour of the Rangoon naphtha, indicating the presence 
of eupione. Dr Tomson obtained, by rectification, naphtha of 
753, and boiling at 320°; while the eupione first described by 
Rercuenzacn boiled almost precisely at the same temperature, , 
and had the sp. gr. .740. Some naphtha sold in Paris for pre- 
serving potassium, which is colourless and very free from oxygen, 
yielded to me by two successive rectifications, a liquid of sp. gr: 
755, almost exactly that of Dr ‘l'aomson’s rectified Persian 
naphtha. Saussure obtained from the naphtha of Amiano, a li- 
quid of sp: gr. 758, boiling at 186°, thus approaching more near-. 
ly to the boiling point of Eupione. 
