b PRESIDENT S ADDRESS. 



The occurrence of a comparatively large amount of potas- 

 sium-nitrate in the leaves of Solaiidra has been observed. 

 Considerable interest is attached to this fact since the storage 

 of nitrates, in other than very small amounts, is confined to a 

 few plants only. 



The constituents of the Sassafras tree of New South Wales, 

 Doryi)]ioia mamfrai^ have been investigated. A volatile 

 essential oil has been obtained from the bark from which also 

 an alkaloid has been separated. The amount of oil obtained 

 from the bark is about 1 per cent. It is a fragrant oil and 

 contains camphor among its constituents. 



With Dr. Chapman, Dr. Petrie has continued the e.^ami- 

 nation of the action of the latex of Euphorbia pejdus on a 

 photographic plate. Evidence has been obtained that the 

 effect on the plate is not due to a gas or emanation given off 

 from the dried juice. It is probable that the photographic 

 action is due to a particle travelling approximately in a 

 straight line and with a moderate velocity. 



The Linnean Macleay Fellow in Geology, Mr. Le<j A. Cotton, 

 who has now rejoined the teaching staff of the Sydney Uni- 

 versity, reports that the earlier part of the year was devoted 

 to the preparation of his memoir on the Ore-Deposits of Borah 

 Creek, since published in our Proceedings. In this he traced 

 an interesting connection between the sulphide ores and the 

 related tin-deposits. Mr. Ward, of the Geological Survey of 

 Tasmania, has been engaged in similar studies in his State. 

 The results simultaneously and independently reached in New 

 England and Tasmania confirm each observer in his conclu- 

 sions. 



In the field, Mr. Cotton resumed his investigations of the 

 diamond-deposits at Copeton. After this he examined the 

 wolfram-ores at Torrington, where recent mining develop- 

 ment provided excellent opportunities of observation. These 

 cres are important from a genetic point of view, being closely 

 related to the tin ore-deposits. Indeed it is becoming clear 

 that the formation of the wolfram-deposits is an integral part 



