102 DISCUSSION. 



Discussion. 



In reply to Mr. W. A. Dixon, Mr. Maiden stated that the 

 samples treated by him were dried at a temperature of 100° C, 

 and that some had taken several days to dry and were weighed 

 from a desiccator. The percentages of tannin obtained by him 

 instead of being higher than the calculations of anybody else were 

 actually lower in some cases. Baron Yon Mueller for instance 

 gave in one case 54 per cent., for Acacia decurrens, while he (Mr. 

 Maiden) had not been able to get within 2 2 per cent, of that. Unless 

 the barks are dried at a constant temperature it was impossible 

 to get satisfactory results, they would give one result in June and 

 a different one in August. 



In answer to questions of Mr. J. T. Wilshire, Mr. Maiden said 

 that Limestone was the only formation which was known for 

 certain to yield barks weak in tannin. (2) That the Acacia vestita 

 which is so rich in tannin is comparatively rare in well settled 

 districts. It is so handsome a tree that it is generally cut down 

 very ruthlessly, but exists in some quantity in parts of Gippsland. 

 (3.) That there was no chance of the dyes obtainable from the 

 Eucalypts and Acacias ever rivalling in quality or price the 

 aniline dyes. 



The President in presenting the thanks of the Society to Mr. 

 Maiden for his paper, intimated that very little importance could 

 be placed on the geological formations in regard to the properties 

 of the trees growing upon them, except in certain localities. So 

 much depended on the climate and the elevation. Certain trees 

 found growing for instance at Sydney in the sand, and at an 

 elevation of 3,000 feet perhaps the same trees would be found 

 growing in a clay soil. A southern aspect seems however, the 

 most essential for their thorough growth, and some derive more 

 moisture from gullies sloping in a southerly direction. In Sydney 

 alone, many varieties of the Wattle would grow admirably and 

 pay well to do so, and it is important that by researches such as 

 these we should know what varieties can be most profitably 

 grown, 



