106 FIRESIDE SCIENCE. 



The other agents have been employed alone and 

 in such combinations as were demanded to conduct 

 the experiments understandingly, and in accordance 

 with correct scientific deductions. It would require 

 too much space to give a detailed account of these 

 experiments ; the statement presented is a general 

 one, given for the purpose of affording a compre- 

 hensive idea of the extent and nature of the labors 

 undertaken, and as preparatory to the presentation 

 of the details of a few experiments of a more special 

 character. During the past three years attention 

 has been given to the production, saving, and appli- 

 cation to the soil of animal excrements, and these 

 observations ought not to pass unnoticed. 



The cost of the bones and most of the other 

 agents used upon the farm was less than they could 

 be obtained for at the present time, as they were 

 purchased during the years of great depression 

 which existed in the time of the war. Twelve tons 

 of raw, unground bones were purchased at the start, 

 at a cost of only twelve dollars per ton. They were 

 placed in a large steam-boiler, constructed of iron, 

 and submitted to the action of high-pressure steam 

 for a period of twelve hours. They were then re- 

 moved, allowed to cool, and immediately reduced 

 to powder by grinding in a machine resembling a 

 common burr-mill. Bones by steaming are changed 

 in their physical structure ; the animal portion ov 



