the Petroleum of Rangoon. 123 
naphtalic, which, like other acids, neutralizes bases and forms 
salts with them. A single glance will satisfy every one how com- 
pletely this account of the properties of naphtaline differs from 
the description given above of the properties of petroline. 
It remains for me to determine its elementary composition. 
This I have not hitherto found leisure to accomplish ; but I am 
engaged in the requisite experiments at the present moment, 
and will soon make them known to the Society. The experi- 
ments hitherto made merely enable me to say, that it contains a 
very large proportion of carbon. 
APPENDIX.—December 1884. 
A few months after the preceding paper was read before the 
Royal Society, the author observed in BucHNER’S Repertorium, an 
account of the discovery, in 1830, by Dr RrIcHENBACH, of a new 
crystalline principle in tar, to which that chemist gave the name 
of Paraffine. As the properties of paraffine seemed from that 
account to be obviously identical with those of the Petroline of 
the Rangoon petroleum, and as Dr RericHENBACH had ascer- 
tained its properties and composition fully, any farther investi- 
gation of the crystalline matter of petroleum appeared unneces- 
sary. ‘The original paper is now published, partly because allu- 
sions have been made to it in chemical works, and partly to serve 
as an introduction to the ulterior inquiry of Dr Grecory on the 
same subject. 
The author, soon after laying this paper before the Royal So- 
ciety, examined by the same process the petroleum of St Cathe- 
rine’s near Edinburgh, of Rochdale in Derbyshire, and of the 
island of Trinidad ; but was unable to detect a similar crystalline 
principle in any of them. 
