362 On Paring and Burning. 



natural condition, I found that 1 acre Lad furnished 14 tons 

 17 cwt. 2 qrs. 11 lb., or, in round numbers, 15 tons of red ashes. 

 A large sample, amounting to several pounds, taken at the 

 same time when the ashes were weighed, was finely powdered, 

 well mixed together, and in a portion of it the amount of water 

 determined at once : — 



1st Exp. 2nd Esp. Average. 

 Amount of water in 



red aslaes when weighed .. 22-30 22-0-i 22-20 



According to these determinations, the rough produce per 

 acre, amounting to nearly 15 tons of ashes, will give 11 tons 

 11 cwt. 2 qrs. 4 lbs., or nearly 12 tons of perfectly dry ashes 

 (dried at 212°). 



As ashes are sometimes mixed with superphosphate and drilled 

 in for turnips, and the ashes usually measured out, I may observe 

 that I find the weight^ of a bushel of red ashes, on an aver- 

 age, to amount to 72^ lbs. This weight refers to ashes not 

 sifted, but just as they are when taken from the heap. Finely 

 sifted ashes of that kind, I imagine, would weigh rather more. 



A well-prepared fair average sample was next used for ana- 

 lysis, and, in the state in which it was analysed, found to 

 contain I'lS per cent, of accidental moisture. This sample 

 had a dull or dirty red colour, due to oxide of iron and some 

 charcoal not completely burned off. Much, however, of what is 

 mentioned in the following analj^sis under Organic Matter and 

 Water of Combination, I am inclined to think is water of com- 

 bination, and arises from the admixture of unburnt soil. 



The following table exhibits the composition of these ashes : — 



Composition of Bed, so-called Vegetable, Ashes from a Field on College Farm, 



Cirencester. 



Moisture .. I'lH 



Organic matter and water of combination .. 3-32 



Oxides of iron and ahunina 18-42 



Carbonate of lime 8*83 



Sulphate of lime I'lS 



Phosphoric acid '71 



(ecjual to bone-earth) (1-5G) 



Potash 1-08 



Chloride of sodium 1-03 



Magnesia 1*76 



Insoluble silicious matter 62-52 



100-00 



These analytical results suggest one or two observations : — 

 1. It will be observed tliat the proportion of phosphoric acid 

 in these ashes is considerable in comparison with the amount of 

 this acid found in soils. Even in very fertile land it rarely 

 amounts to two-tenths or thi-ee-tenlhs of one per cent. 



