FERTILIZERS. 263 



face upon which the atmospheric and other agents may act. To this I should add that in pro- 

 portion to the state of comminution, so will the rapidity of their action be ; and it follows, 

 again, that where action is energetic, it must also consume in a comparatively less time the 

 • matters upon which those agents are at work. There is a want of information upon the ques- 

 tion, what degree of fineness is the most economical ? It is evident that there is.a certain de- 

 gree of comminution which will yield the farmer the highest profit. 



9. Bones. 



The composition of bones has been given in the second volume of the Agriculture of New- 

 Ycjrk. Compare the composition of bones wath many of the products of vegetation ; we shall 

 then be led to appreciate the value of all those substances which contain phosphates, as ferti- 

 lizers. We may imagine the phosphoric acid of the soil first transferred to the constitution of 

 vegetables, and then removed upward again to the bodies of animals.. All the important 

 fluids and solids of animals are pervaded with the salts of phosphorus. 



Bones and the phosphates owe a portion of their value to their bulk ; the valuable matters 

 are concentrated in them so that they constitute a portable fertilizer — may be transported, with- 

 out loss, a great distance, and yield a large profit by their application. In this and the New- 

 England States, which have now lost much of their primeval fertility, portable manures must 

 become of great importance. Experience will finally prove, if it has not already proved, that 

 good cultivation is the most profitable husbandry ; and, of course, good cultivation demands 

 an application of fertilizers, since llelds which have yielded their increase for one and two 

 centuries, must be measurably exhausted of their original stock ot the more expensive vegetable 

 aliments. 



On consulting the composition of bones, it will be observed that they consist, in the first 

 place, of two distinct parts — an organic and inorganic part : the first is known under the name 

 of gelatine, the latter that of the salts of lime, soda and magnesia, in combination with phos- 

 phoric acid. Since bones have come into use as fertilizers, the question has been agitated, 

 whether the organic part contributes to the effect attributed to bones 1 Great names are found 

 on both sides. Sprexgel and Liebig maintained that the fertilizing effects of bones came from 

 the inorganic part; and that if bones were burned, by which all their organic matters were dis- 

 sipated, they would be equally valuable. Johnston, of Durham, on the contrary, has col- 

 lected facts which go to disprove this view, and to substantiate the claim of organic matter as 

 an efficient fertilizer. It is admitted, and indeed, proved, that the inorganic part is a fertilizer 

 per se ; and I am led to entertain the opinion that it is the most valuable and most important 

 part of bones. The gelatine of bone contains, 



Carbon 5037 



Hydrogen, 6-33 



Nitrogen, 17-95 ^ 



O.xygen, 25 • 35 Johnston. 



