VALUE OF HUMAN EXCREMENTS. 19/ 



tity of manure consumed by this and that plant, 

 is expressed in hundredth parts, and yet we know 

 not what manure is ! 



If we admit that the liquid and solid excrements 

 of man amount on an average to 1^ Ibs. daily 

 (fib. urine and % Ib. faeces), and that both taken 

 together contain 3 per cent, of nitrogen, then hi 

 one year they will amount to 547 Ibs., which 

 contain 16*41 Ibs. of nitrogen, a quantity sufficient 

 to yield the nitrogen of 800 Ibs. of wheat, rye, oats, 

 or of 900 Ibs. of barley. (Boussingault.) 



This is much more than it is necessary to add to 

 an acre of land, hi order to obtain, with the assist- 

 ance of the nitrogen absorbed from the atmo- 

 sphere, the richest possible crop every year. Every 

 town and farm might thus supply itself with the 

 manure, which besides containing the most nitro- 

 gen,, contains also the most phosphates ; and if an 

 alternation of the crops were adopted, they would 

 be most abundant. By using, at the same time, 

 bones and the lixiviated ashes of wood, the excre- 

 ments of animals might be completely dispensed 

 with. 



When human excrements are treated in a proper 

 manner, so as to remove the moisture which they 

 contain without permitting the escape of ammonia, 

 they may be put into such a form as will allow 

 them to be transported, even to great distances. 



This is already attempted in many towns, and 

 the preparation of human excrements for trans- 



