Value of Earth- Closet Manure. 
201 
amount of faeces and urine which is produced hy a mixed popu- 
lation of adults and children of both sexes ; but it may be 
safely stated that the amount of dry matter in the solid and liquid 
excreta of a mixed population does not exceed 56 lbs. per 
head per annum, and that probably it is not more than 45 or 
46 lbs. In some experiments which Professor Way made upon 
adults, he found that an individual voids in 24 hours about ^ lb. 
of faeces and 3 lbs. of urine. Assuming the preceding^ ana- 
lysis fairly to represent the composition of the solid and liquid 
excreta of man, and each person of a population to produce ^ lb. 
of faeces and 3 lbs. of urine in 24 hours, we obtain in 
Per annum. 
4 ozs.'of feces 1 oz. of dry matter, or in round numbers nearly 23 lbs. 
and in 
3 lbs. of urine Ij oz. of dry matter, or in round numbers nearly 34 Ib.s. 
Thus the liquid excreta of man contain one-half more dry 
matter than the solid. 
On calculating the amount of ammonia which will be pro- 
duced on the decomposition of the dry matter of the solid and 
liquid excrements of each person per annum, we obtain from the 
Ammonia. 
23 lbs. of dry matter contained in the solid excreta .. .. 1' 60 lbs. 
and in 
34 lbs. of dry matter contained in the liquid excreta .. .. 8"12 lbs. 
or altogether 9'72 lbs. 
In other words, five-sixths of the ammonia capable of being 
generated on the decomposition of human excreta is furnished by 
the urine. By a similar calculation I find that, according to 
the preceding data, each individual would furnish about 5^ lbs. 
of phosphates per annum. For simplicity's sake we may assume 
that each person of a population produces in the solid and liquid 
excreta 56 lbs. of dry matter per annum. These 56 lbs. produce 
in round numbers 10 lbs. of ammonia, and 5^ lbs. of phosphates. 
In order to avoid the appearance of a wish to undervalue the 
intrinsic fertilizing value of human excreta, I would allow 9d. 
per lb. for ammonia, and 2d. per lb. for phosphates, and further 
9c?. for the money-value of the remaining constituents, which is 
rather more than the latter are really worth. 
The excreta of each person of a population accordingly would 
be worth per annum 9a., allowing 
s. d. 
For 10 lbs. of ammonia at 9d. per lb 7 6 
„ 5^ „ of phosphates at 2c?. per lb Oil 
„ other matters 0 7 
Total value of human excreta per head per 
annum 0 
