BONE MANURE. 183 



With every 110 lbs. of the lixiviated ashes of the 

 beech which we spread over a soil, we furnish as 

 much phosphates as 507 lbs. of fresh human excre- 

 ments could yield. Again, according to the analysis 

 of De Saussure, 100 parts of the ashes of the grain 

 of wheat contain 32 parts of soluble, and 44-5 of 

 insoluble phosphates, in all 76-5 parts. Now the 

 ashes of wheat straw contain 11*5 per cent, of the 

 same salts; hence with every 110 lbs. of the ashes 

 of the beech, we supply a field with phosphoric acid 

 sufficient for the production of 4210 lbs. of straw 

 (its ashes being calculated at 4*3 per cent, De 

 Saussure), or for 16-20000 lbs. of corn, the ashes of 

 which amount, according to De Saussure, to 1*3 per 

 cent. 



Bone manure possesses a still greater importance 

 in this respect. The primary sources from which 

 the bones of animals are derived are, the hay, straw, 

 or other substances which they take as food. Now 

 if we admit that bones contain 55 per cent, of the 

 phosphates of lime and magnesia (Berzelius), and 

 that hay contains as much of them as wheat strait, 

 it will follow that 8*8 lbs. of bones contain as much 

 phosphate of lime as 1102 lbs. of hay or wheat- 

 straw, and 2*2 lbs. of it as much as 1102 lbs. of the 

 grain of wheat or oats. These numbers express 

 pretty nearly the quantity of phosphates which a 

 soil yields annually on the growth of hay and corn. 

 Now the manure of an acre of land with 44 lbs. of 

 bone dust is suflGicient to supply three crops of wheat, 



abies (which is composed of 3 per cent, phosphate of lime and potash), 

 but by its actual detection in the ashes of pines and other trees. — 100 

 parts of the ashes of wood ofpinus abies give 3 per cent, phosphate of 

 iron; 100 parts of the ashes of the coal of pinus syhestris give 1 72 

 phosphate of lime, 0*25 phosphate of iron ; 100 parts of ashes of oak 

 coal g-ive 7-1 phosphate of lime, 3-7 phosphate of iron ; 100 parts of the 

 ashes of bass wood give 5 4 phosphate of lime, 3*2 phosphate of iron ; 

 100 parts of the ashes of birch wood give 7-3 phosphate of lime, 1'25 

 phosphate of iron; 100 parts of the ashes of oak wood give 1-8 phos- 

 phate of lime ; 100 parts of the ashes of alder coal give 345 phosphate 

 of lime, 9 phosphate of iron. These are the calculated results from 

 Berthier's analyses." — Dr. S. L. Dana, in Report on a Reexamination 

 of the Economical Geology of Massachusetts. 



