512 Royal Society : — 



" Chemical Examination of Burmese Naphtlia, or Rangoon Tar." 

 By Warren De la Rue, Ph.D., F.R.S., and Hugo Miiller, Ph.D.* 



In several localities of tlie kingdom of Burmah, there emanates 

 from the soil in considerahle quantity a peculiar oleaginous substance, 

 which is employed for a variety of purposes, but chiefly as a lamp- 

 fuel and as an unguent, by tlie natives, and exported in moderate 

 quantities under the name of Burmese naphtha, or Rangoon tar. ^ 



It is obtained by sinking wells of about 60 feet in depth, in which 

 the liquid is collected by the miner as it oozes from the soil. 



At the common temperature this substance has the consistence of 

 goose-fat; it is lighter than water, has usually a greenish-brown 

 colour, and possesses a slight odour, peculiar, but not disagreeable. 

 It consists almost entirely of volatile constituents. 



Burmese naphtha has already attracted the attention of other 

 chemists ; at present we refrain from entering into a discussion of 

 their results, since it is our intention to give a full history of this 

 remarkable natural product when, after the completion of our expe- 

 riments, we shall have the honour of submitting to the Royal Society 

 a detailed account of our investigation. The object of the present 

 communication is to trace a mere outline of the residts at which we 

 have arrived up to this moment. 



The circumstances under which petroleum — for this is the col- 

 lective term which comprehends a great variety of oily emanations 

 similar to Burmese naphtha — occurs in nature, all tend to prove that 

 these substances are the products of a slow destructive distillation of 

 the residuary matter of a prhneval creation : this bemg admitted, the 

 idea naturally suggested itself of examining this substance in com- 

 parison with the products of artificial destructive distillation. 



With this view, one of usf was induced to procure, through the 

 intervention of a friend, several tons of Rangoon tar, which was care- 

 fully collected at the soiirce, and transmitted to Europe in well-secured 

 vessels. Our experience in the course of this iuquirj^ has shown 

 that this quantity, large as it may appear, was by no means too 

 ample a supply, liurmese naphtha contains indeed so great a variety 

 of substances, and some of them in so exceedingly minute a propor- 

 tion, that even the large amount of material at our disposal was in- 

 sufficient for the complete examinatioii of several constituents, the 

 presence of which we had succeeded in establishing beyond a doubt. 

 As an example, we may state that Burmese naphtha contains small 

 quantities of organic bases, the study of which we were compelled to 

 postpone to a later period, when an additional quantity of material, 

 which is now on its way to Europe, will have come to hand. 



We have already mentioned that Rangoon tar is almost entirely 

 volatile, and preliminary experiments proved to us that the distilla- 

 tion could be effected most conveniently, and vnih less danger of ob- 

 taining products of decomposition, in a current of steam ; first of a 

 temperature of 100° C. (212° F.), and subsequently of steam super- 



* This paper was received during the Recess, and printed in No. 22 of the 

 ' Proceedings.' 



t Warren De la Rue. 



