MANURIAL VALUE OF ASHES, "MUCKS," ETC. 87 



■crops; not to deposit on the land fertilizers which ma" last for 

 three or four years, but by prompt, efficacious action to render 

 a quickly remunerative return from a moderate outlay." The 

 chief objection to the use of bone meal is, indeed, the slowness 

 with which it becomes available. 



THE COMPOSITION OF BONE. 



Raw bone usually carries nearly six per cent of nitrogen and a 

 little less than twenty per cent of phosphoric acid. The Maine 

 analyses of locally ground bone meals have been found to vary 

 within not very wide limits. The nitrogen in these meals usually 

 runs from about 3.75 per cent to 4.25 per cent and the phos- 

 phoric acid from about twenty-one to twenty-three per cent. The 

 imported bone meals sold by manufacturers of commercial fertil- 

 izers will frequently run lower than this, but their composition 

 can be ascertained from the guarantees which the manufact- 

 urers place upon the packages. The average bone meals as 

 turned out in the Maine mills can be expected to carry about four 

 per cent of nitrogen and about twenty-two per cent of phospho- 

 ric acid. 



BONE MEAE AND WOOD ASHES. 



As shown from the above composition, bone meal is not a com- 

 plete fertilizer in that it contains no potash. The practice which 

 is quite common in Maine of mixing bone meal with wood ashes 

 is a good one, not only because the wood ashes supply the lack 

 of the bone in potash, but help to render the nitrogen and phos- 

 phoric acid more quickly available. Just what changes take 

 place when bone and ashes are mixed together, and kept moist, 

 are not as clearly known as is the action of sulphuric acid upon 

 bone phosphate. Probably the potash of the ashes tends to 

 saponify the fat and bring more or less of the other organic mat- 

 ters into solution. If the fermen cation goes on in a heap, pre- 

 cautions should be taken to prevent loss of nitrogen. The action 

 of the ashes upon the organic part of the bones causes the 

 mineral part of the bone to disintegrate to a greater or less 

 extent. There is no evidence, however, that the phosphate of 

 lime in the bone undergoes any chemical change because of the 

 ashes, or that it is any more available to the plants, onlv so far 



