BON' 



BON 



per acre is ten or twenty bushels for ' 

 five years' rotation, or, in composts, 

 two or four bushels annually. The 

 effects are most remarkable on sandy 

 and light soils ; but all lands are im- 

 proved by it when the addition is in- 

 dicated. The lest, when bones arc 

 necessary, is easily discovered ; for 

 soils which produce defective grain 

 are always much benefited by them. 



The value of bone dust arises from 

 the fact that all seeds contain a large 

 quantity in their ashes, and the soil 

 is naturally but poorly supplied. Seed 

 crops are well known to exhaust 

 lands rapidly, and chiefly because they 

 remove the bone earth or phosphates 

 of the soil. Those lands which are 

 well furnished with this substance 

 naturally produce rich clover and 

 wheat : such are marls, some second- 

 ary limestones, and stiff clays, and 

 show less the application of bones. 



The dust is to be scattered with 

 seed, and not ploughed in deep ; for it 

 has a tendency to sink naturally, and 

 as it is very slowly dissolved by rain 

 water, it should not be placed out of 

 the reach of plants. Compared with 

 farm-yard manure, one bushel is 

 equivalent to three cart loads, wher- 

 ever it is well applied. 



All plants, the shells of lobsters 

 and eggs, and the fine shell marl of 

 ponds contain bone earth ; and in 

 Spain a mineral is extensively found 

 consisting of nearly pure phosphate 

 of lime ; but the principal source is 

 from bones. Guano often contains 

 twenty-five per cent, of phosphates. 

 The action of this substance, in what- 

 ever combination it may exist, is al- 

 ways the same. 



Bones which have been boiled be- 

 fore grinding are very little inferior 

 to the recent, except when applied to 

 very poor soils, where the putrescent 

 animal matter is required. Recent 

 bones are best for turnips, cabbages, 

 and similar crops ; but the boiled va- 

 riety answers for grass, grains, pease, 

 beans, &,c., the manure being adapted 

 for every crop cultivated for seeds. 



BONES, DISSOLVED. For the 

 purpose of obtaining the full action 

 of bone dust in the shortest time, it 

 100 



is dissolved in oil of vitriol (sulphuric 

 acid) or in muriatic acid. The strong 

 acids are used for this purpose at the 

 rate of fifty to sixty pounds of acid 

 to two bushels of dust. The acid 

 should be slightly diluted if it black- 

 ens the bones. They should be stir- 

 red with a wooden stick, and the op- 

 eration conducted in a large crock 

 of coarse earthen-ware. The great 

 causticity of the acid renders it a 

 nice process. The solution should 

 be taken up with fine soil or mould, 

 and one half applied to an acre as a 

 top dressing, care being always taken 

 that before use it has lost its acid 

 qualities. 



In this way a soluble phosphate of 

 lime and sulphate of lime are formed : 

 the latter remains at the bottom of 

 the vessel, and is a fine plaster of 

 Paris ; it should be stirred up with 

 the mixture when the soil is added. 

 When fresh bones are used, the gel- 

 atin also thickens the solution. This 

 preparation of bones is now superse- 

 ding the common application in Eng- 

 land and Scotland for turnips. When 

 employed, it should be sown with the 

 seed, or used as a top dressing to 

 ysung plants. It will be found an 

 admirable ingredient for composts in- 

 tended to bring forward seed crops. 



BONE EARTH. Phosphate of 

 lime chiefly. 



BONE MILL. The following ac- 

 count of a mill for breaking bones into 

 small fragments is from Mr. Rham : 



The mill to break and grind bones 

 consists of two iron or steel cylin- 

 ders, with grooves running round 

 their circumference, the projections 

 being cut so as to form strong teeth. 

 These turn upon one another by 

 means of machinery, so that the 

 teeth of one run in the groove be- 

 tween the teeth of the other, as may 

 be seen in the annexed cut. 



The bones put in the hopper, 0, are 

 seized by the teeth of the two upper 

 cyhnders, and broken in pieces, which 

 fall in between the lower pair, where 

 they are reduced to a smaller size. 

 From these they fall on a slanting 

 board, D, and slide into the wire cyl- 

 inder. All the smaller pieces pass 



