BONES. 



205 



more seed or grain -forming ingredients, than straw 

 or the faeces of animals. 



Compared with good and bad guano, we find the 

 following differences : — 



Whilst, therefore, bone-dust is 2J times poorer in 

 forcing substances than good guano, it possesses, on 

 the other hand, double the quantity of those ingre- 

 dients which form the seed or grain ; and whilst it is 

 from 3 to 4 times richer in nitrogen than bad guano, 

 it is in turn greatly surpassed by the large amount 

 of phosphate of lime that is present in the latter. 



From the results of practical experience in Saxony, 

 it may be assumed that the entire effect produced 

 by 1 cwt. of bone-dust is equal to that of from 25 

 to 30 cwt. of stable-muck, and that from 2 to 2^ 

 cwt. are necessary to develop the full effect of 1 cwt. 

 of Peruvian guano. Accordingly, 1 cwt. of bone- 

 dust would be able to produce at least 2 or 2J Saxon 

 bushels (320 to 400 lbs.) of rye grain, besides a cor- 

 responding quantity of straw. On soils which are 

 not too binding, the action of finely levigated bone- 

 dust may, on an approximative calculation, be so 

 distributed as to amount, in effect, in the first and 

 second years, to from 25 to 30 per cent. ; in the third, 

 18 



