204 



a small amount of carbon dioxide gas evolved on dissolving" 

 the asih in hydrochloric acid, so that the lime not present 

 as calcium sulphate would be present chiefly as calcium oxide, 

 CaO. It is this substance which liberates the piturine during- 

 mastication 



The presence of such a high percentage of calcium sulphate 

 seemed to me to be remarkable and it was thought that a 

 comparison of this ash with some others obtained from Ausr 

 tralian bushes would prove interesting. Professor Rennie 

 kindly pointed outi to me that some years ago Mr. W. A. Dixon, 

 of Sydney, had made some analyses of the ash of various Ausr- 

 tralian bushes. His results were published in the Proceedings 

 of the Royal Society of New South Wales, vol. xiv. I re- 

 ferred to this paper, and found thait in no case does any 

 analysis, out of the eight given, show the presence of more 

 than 4.5 of sulphuric anJiydride, and thait the lime present is- 

 very much less than in the ash of the Acacia salicina. 



I give two of the determinations of sulphuric anhydride and 

 lime made by Mr. Dixon^: 



(1) Dwarf Saltbush (2) Cotton Bush 



{A triplex sp.). (Chenolea hicornis). 



Lime CaO 17.74% ... CaO 24.33% 



Sulphuric anhydride SO. 4.43 ... SO. 3.95 "^ 



An analysis of the ash of the Alstonia constricta, "Fever 

 bark," published by Mr. Maiden, shows a higher percentage 

 of lime and sulphuric) anhydride than the above, viz. : 



Lime CaO ... 32.83% 



Sulphuric anhydride ... SO. ... 9.33 



It will be seen that none of these ashes contain nearly so 

 much lime and sulphuric anhydride as the ash of the Acacia 

 salicina. 



There does not appear to be much published matter with 

 regard to the ashes of plants, &c., and it is impossible, there- 

 fore, to make an extensive comparison of this ash with others. 

 Phillips and Bauerman, in their work on Metallurgy, give a 

 few analyses of the ash of some Europeaai woods, and I find 

 from these that the percentage of calcium sulphate present 

 is less than it is in the ashes of the Australian woods already 

 mentioned. 



The results given below are calculated as calcium sulphate : 



1. Beech, from Switzerland ... 2.3% ... Ca SO^ 



2. Scotch Fir, from Giessen ... 3-31° ... Ca SO^ 



3. Scotch Fir, from Giessen ... 5.05 ... Ca SO4 



It seems to me that there is little doubt that the calcium 

 sulphate is present in the ash of th.© Acacia salicina in much 

 larger quantity than in a.ny other ash at present known to us. 



