64 BOARD OF AGRICULTURE. 



same as animals; and here the parallel of comparisou 

 ends. 



The mind in its functions is a force or power ; and it must 

 be fed or recuperated the same as any other force, or it be- 

 comes weak and abnormal. As regards separate forces in 

 the living economy, we will assume that animals are con- 

 trolled by two that are specially distinctive, — those arising 

 from the nitrogenous and carbonaceous foods ; while man 

 is under the influence of three or more, the phosphatic force 

 being peculiar and distinctive, as needed in an organism 

 controlled by mind. What instinct is we do not know : we 

 do know, however, that, like mind, it exists in greatly modi- 

 fied forms. There is just as much difference in the instinct 

 of horses and oxen as there is in the minds or intellectual 

 force of men ; and it may be that this difference is manifest 

 in the chemical nature of the excretions, as is shown in that 

 of the highest order of animals. It may be that the waste 

 of a highly intelligent or nervous horse is less valuable as 

 plant-food than that of a dull, lazy animal: we strongly 

 incline to think that it is. This modification, if it exists, is 

 due to the action of animal mind or instinct solely : it his 

 nothing to do with the modifications resulting from the 

 exercise of the muscular forces. 



The excretions of a working or a dray horse are not as 

 valuable as those of a pampered animal, — one kept in the 

 stall two-thirds of the time. The working animal uses up the 

 nitrogenous element in his daily labor : the other rejects 

 it through the alimentary and urinary canals. The excretions 

 of students and persons engaged in hard manual labor are 

 less valuable as plant-food than those from lazy, indolent 

 individuals who think and work but little. The lost waste 

 of the students and hard workers is in the direction of the 

 phosphates and the nitrogen, — two of the most important 

 agents needed by plants. The exhaustion of the important 

 principles of plants in the human economy is under all 

 circumstances greater than in the animal, and this is shown 

 by analysis. The agency of the mind upon foods, even in its 

 dullest manifestations, is very great ; and human excrement 

 must necessarily occupy a low place among fertilizing agents 

 in the scale of values. 



The analysis of human excretions in their combined form, 



