BONE MANURE. 17T 



wheat-straw, then it follows that 8 lbs. of bones contain as much 

 phosphate of lime as 1000 lbs. of hay or of wheat-straw, and 20 

 lbs. as much phosphoric acid as 1000 lbs. of the grain of wheat 

 or of oats. These numbers are not absolutely correct, but they 

 give a very fair approximation of the quantity of phosphates 

 yielded annually by a soil to these plants. By manuring an acre 

 of land with 60 lbs. of fresh bones, we furnish sufficient manure 

 to supply three crops (mangel-wurzel, wheat, and rye) with 

 phosphates. But the form in which they are restored to a soil 

 does not appear to be a matter of indifference. For the more 

 finely the bones are reduced to powder, and the more intimately 

 they are mixed with the soil, the more easily are they assimi- 

 lated. The most easy and practical method of effecting their 

 division is to pour over the bones, in a state of fine powder, half 

 their weight of sulphuric acid diluted with three or four parts of 

 water, and after they have been digested for some time, to add 

 about one hundred parts of water, and to sprinkle this acid mix- 

 ture (phosphates of lime and magnesia) before the plough. In & 

 few seconds, the free acids unite with the bases contained in the 

 earth, and a neutral salt is formed in a state of very fine division. 

 Experiments instituted on a soil formed from grauwacke, for the 

 purpose of ascertaining the action of the manure thus prepared, 

 have distinctly shown that neither corn nor kitchen-garden plants 

 suffer injurious effects in consequence ; but that, on the contrary, 

 they thrive with much more vigor.* 



In the manufactories of glue, many hundred tons of a solution 

 of phosphates in muriatic acid are yearly thrown away as be 

 ing useless. It would be important to ascertain how far this 

 solution might be substituted for bones. The free acid would 



* Very favorable results have been obtained by treating seeds in the fol 

 lowing manner: — The seeds about to be sown were steeped in the water 

 from a dunghill, and while still wet, were strewed with a mixture of 20 

 parts of fine bone-dust and 1 part of burnt gypsum, in such a manner that 

 each grain was covered with a thin layer of the powder ; by sprinkling 

 them with water and repeating this treatment with the mixture, the coat- 

 ing can be increased. The seeds were allowed to dry in the air, and were 

 then sown in the usual way. On the large scale this mode of dunging 

 owing to its being rather troublesome, might not answer the purpose M 

 well as a heavy manuring with bones and gvpsum. 

 9* 



