WOOD ASHES 529 



448. Wood Ashes. Unleached wood ashes furnish an im- 

 portant quantity of potash fertilizer. The composition of the 

 ash of woods is extremely variable. Not only do different varie- 

 ties of trees have varying quantities of ash, but in the same 

 variety the bark and twigs will give an ash quite different in 

 quantity and composition from that furnished by the wood itself. 

 In general the hard woods, such as hickory, oak, and maple, 

 furnish a quality of ash superior for fertilizing purposes to that 

 afforded by the soft woods, such as the pine and birch trees. 



The character of the unleached wood ashes found in the trade 

 is indicated by the subjoined analyses. The first table contains 

 the mean, maximum and minimum results of the analyses of 

 97 samples by Goessmann. 21 



Composition of wood ashes. 

 Means Maxima Minima 



Potash 5-5 io-2 2.5 



Phosphoric acid 1.9 4- -3 



Lime 34'4 5-9 l8 - 



Magnesia 3-5 7-5 2 -3 



Insoluble 12.9 27.9 2.1 



Moisture 12.0 28.6 0.7 



Carbon dioxid and undetermined 29.9 



In 1 6 analyses made at the Connecticut station the data ob- 

 tained are given below: 22 



Means Maxima Minima 



Potash 5-3 7-7 4-0 



Phosphoric acid i-4 *-8 i-9 



In 15 analyses of ashes from domestic wood-fires in New Eng- 

 land, the following mean percentages of potash and phosphoric 

 acid were found: 



Potash 9- 6 3 



Phosphoric acid 2 '3 2 , 



In leaching, ashes lose chiefly the potassium carbonate and 

 phosphate which they contain. Leached and unleached Canada 

 ashes have the following composition: 



21 Annual Report of the Massachusetts Agricultural Experiment Station, 



1888 : 202. 



" Annual Report of the Connecticut Agricultural Experiment Station , 



1889 : no. 



