president's address. 489 



poor sulphides {i.e. 6 per cent.) found with gold in excess of 

 antimony is added a bronze like metallic alloy, which is brittle 

 and which the amalgam will not touch. It forms into flaky 

 crystals which even after long continued grinding retain the 

 scale-like character and are thus easily carried away by water. 

 Mr. Newbury roasts the ore with salt or other chloride, and when 

 raised to a red heat exposes it to a jet of steam, by which the 

 gold is reduced to a bright clear state, easily affected by the 

 amalgam. 



The researches of Mr. A.W. Howitt, F.GKS., on the microscopical 

 characters of the diorites and granite of Victoria are of the 

 highest interest. They show careful observation and extensive 

 knowledge of the subject, and are made in a department of 

 knowledge where hitherto very little has been done. Mr. Ulrich 

 has on several occasions drawn attention to the necessity of this 

 kind of study of our rocks. It has been shown that reefs become 

 richer near some dykes, but not all. By the examination of 

 carefully prepared microscopical sections he has shown that the 

 rocks which have a good influence are of one special variety. 

 They are homhlendic and true diorites, while all the rock masses 

 and dykes which are of augitic diahose have been proved to be 

 non-auriferous as well. Until Mr. Ulrich's observations, all 

 these rocks were classed and maj)ped as diorites, and they cannot 

 be distinguished except in microscopical sections. 



I have thus passed rapidly over the principal fields of science 

 which are at the present moment receiving every elucidation from 

 our colonial workers. I have purposely abstained from any 

 reference to our own Society's work, as the journal of our 

 proceedings is a sufficient evidence of that. But I do not think 

 I ought to allow this address to conclude without an expression 

 of my humble appreciation of the labours of my colleagues in this 

 colony, from whom I have frequently received considerable aid 

 and always much kindness and sympathy. The zeal and public 



