194 H. G. SMITH. 
On tHE CONSTITUENTS or tue SAP or true “SILKY OAK,” 
GREVILLEA ROBUSTA, R. Br., anp THE PRESENCE 
or BUTYRIC ACID THEREIN. 
By Henry G. Smiru, F.c.s. 
{Read before the Royal Society of N. 8. Wales, October 7, 1896.] 
Durine last year, the author in conjunction with Mr. J. H. 
Maiden, carried out investigations on a deposit of Succinate of 
Aluminium, found existing in the timber of Grevillea robusta, R.Br. 
the results of which were communicated to this Society 1 in a paper" 
read on the 6th November. 
The occurrence of succinic acid in a deposit of this character 
appears to be extremely rare, and the origin of its formation was 
a matter for some consideration. As was pointed out at that 
time, it appeared probable, from the result of our inquiries, that 
the acid might have been formed by the alteration of malic acid, 
together with the formation of acetic acid, as a trace of the latter 
acid had been identified in the deposit. As it had not been pos 
sible at that time to obtain the sap from this tree, it was of course 
impossible to say whether malic acid was present or not, so the 
matter was allowed to remain open until the sap could be investi- 
gated. Special efforts were made to obtain, if possible, some of 
the sap, and it is to the kindness of Mr. W. P. Pope, Forester; 
in the Lismore District, of this colony, that I am indebted for the 
present material, he having collected and forwarded a small - 
quantity of the sap for investigation. 
Mr. Pope informs me that he obtained the sap by felling the 
tree, cutting it into lengths, which were then placed on their ends, 
so as to enable them to drain. He says that the sap would not 
run if the tree was merely cut into, or even if cut quite off, but 
1 On a natural deposit of Aluminium Succinate in the tember of 
Grevillea robusta, R. Br. 
