MANURE. 171 



transported to the spot where the further conversion of the 

 night-soil is to take place. Both the ammonia and sulphur- 

 etted hydrogen are too valuable to be lost. No grain ever 

 grew which did not contain sulphur compounds. 



Secondly. The night-soil being deodorized, as above, it is 

 to be removed or transported, by day or by night, as may 

 be most convenient, to the pit prepared for its reception, 

 and then mixed in the mode which has been above set forth, 

 with the charred material. 



Thirdly. The furnace for charring is to be constructed of 

 several hoppers, or very shallow pans, with inclined sides, 

 set one above the other, and surrounded with brick work, so 

 that the fire may play all around the hoppers.- The hoppers 

 must be so constructed as to swivel, so that the contents of 

 each may be easily dropped into the pan immediately below. 



The bottom of each pan is made of thick cast-iron, the 

 lowest pan has a bottom of fire-brick, and is stationary over 

 the grate ; a door leads to it, and its end is movable, so as 

 to allow the charred material to be withdrawn. 



The height of the furnace will be regulated by the num- 

 ber of tiers of pans. It is a large chimney stack, with a fire 

 at its bottom, the flame, smoke, &c., passing among the 

 hoppers. 



The pans are charged with the materials intended to be 

 baked, and the fire is kept up constantly. 



The earth or peat on the lowest hopper, when of a brown- 

 ish red color, and somewhat hot, is to be withdrawn into 

 sheet-iron cylinders, furnished with a tight cover, and cooled 

 while shut up. The materials in the several hoppers are to 

 be successively dropped into those below them, and the upper 

 one recharged with fresh matter. The charge is repeated 

 about once in an hour, the earth, &c., having been previously 

 screened and made fine. 



