Analysis of certain Woods of Tasmania. 89 



standiug a few hours so as to take up the soluble matter, the 

 clear liquor is drawn ojQf, evaporated to dryness in iron pots, 

 and finally fused at a red heat into compact masses, which 

 are grey ou the outside and pink-coloured within. 



The best Canadian potashes, which are sent home in casks 

 weighing about five hundred weight, contain on an average 

 60 per cent, of pure potassa, and the price is, I believe, 

 about £.1 4:S. per cwt. 



In Dr. Ure's Dictionary of Arts and Manufactures, from 

 which the above statement of the mode of manufacturing the 

 potash is extracted, I find a table giving the amount of 

 potassa contained in various woods and vegetables, from 

 which it appears that 



1000 parts of Pine yield 0.45 of Potassa. 



Poplar 0.75 



Beechwood 1.45 



Oak 1.53 



Boxwood 2.26 



Willow 2.85 



Elm and Maple 3.90 



Wheat Straw 3.90 



Oak Bark 4.20 



Thistles 5.00 



Small Eushes 5.08 



Barley Straw 5.80 



Dry Beech Bark 6.00 



Fern 6.26 



Large Eush 7.22 



From the experiments made by Dr. Motherwell, it would 

 appear that the woods of this country, especially that of the 

 she-oak and the white gum, yield a very large quantity of 

 potash, as compared with the elm and the maple, the most 



