OVER-ESTIMATE OF NIGHT-SOIL. 63 



hermetically sealed, it affords a nutritious and palatable dish 

 in the winter months ; and every family should secure a 

 supply. 



Sweet corn should be planted for green forage for animals, 

 as ft contains in a more concentrated form the desirable 

 nutritive principles necessary for milch cows. 



Perhaps the most important of the teachings of the new 

 agriculture relate to improved methods of fertilizing and 

 fitting our fields for the growth of crops. It informs us 

 precisely regarding the nature of the substances in manures 

 which constitute the food of plants : it separates the worth- 

 less from the valuable, and teaches us how best to apply 

 manures to soils. 



It also has opened to us the interesting and transcendently 

 important fact, that nature and art have proved competent 

 to supply in concentrated forms vast quantities of plant-food 

 entirely outside of animal excrement : we have learned that 

 the same salts found in excrement are provided by nature 

 in certain combinations in the most lavish abundance. They 

 do not exist in forms readily assimilable, like those in dung ; 

 but we have learned the simple processes of making them 

 soluble and available, and thus our triumph is complete. • 



Some most interesting facts relating to the comparative 

 ^alues of excrementitious products have been taught us by 

 the new agriculture, and we have learned of the curious varia- 

 tions in their value. We also have learned the reasons for 

 these differences. Let me illustrate this point by considering 

 briefly that form of plant-food known as night-soil. I have 

 been led to conclude that human waste is far less valuable 

 as fertilizing material than that of animals under ordinary 

 conditions. This result has been reached through chemical 

 analysis and practical trials in the field. The changes which 

 foods undergo in passing through the organisms of men and 

 animals differ in a surprising manner; and they arise in a 

 large degree (not solely) from the influence or needs of the 

 mind or intellect present in man, but not in animals. The 

 human machine needs nitrogen to give muscular strength, 

 the same as that of the horse or the ox ; it needs carbon to 

 give warmth, as does that of animals; it needs the phosphatic 

 element and the earthy salts to repair bone-waste and to 

 maintain the blood and secretions in normal condition the 



