( 96 ) 

 thirds after having remained at least a year 

 in the reservoirs, are run off into the Seine. 



We have said that the excrements of a man 

 for one year contain about 20 pounds of Ni- 

 trogen, a sufficient quantity, says Boussin- 

 gault, for the growth of 900 pounds of wheat, 

 rye oroats, or for 1000 pounds of barley. That 

 is to say, these excrements can fertilize a field 

 of 250 square yards, with an assurance of an 

 abundant crop. 



The utilization of the total product of hu- 

 man excrements, of wood and peat ashes, of 

 vegetable and animal matters, would wholly 

 or at least partially supersede the use of barn 

 yard dung. This result would enable the far- 

 mer to dispense with a portion of cattle in 

 those localities where forage is scarce, or the 

 soil is more profitable for the growth of food 

 for a numerous population. 



Schattenmann has very properly insisted 

 upon the value of the phosphates contained 

 in the human excrements, for they certainly 

 play a most important part in vegetation. 



According to Schattenmann, an half gallon 

 of matters, disinfected and saturated with sul- 

 phate of iron, making 2° Baume's hydrome- 

 ter suffice to manure 3h square feet of mea- 



