MANURES. 215 



" national economy will move them, and they have not generally 

 " been educated to the importance of a strict observance of the 

 "laws of health, — not always of those of decency." 



In continuation of the same subject, I publish herewith an 

 article recently furnished to the New York Evening Post : 



THE EARTH CLOSET AND ITS POSSIBILITIES. 



In the 'Journal of the London Society of Arts^ for May 1 6, 

 1863, there is published a series of tables which had been sub- 

 mitted by Dr. Tudichum, concerning the commercial value of the 

 constituents of human excrement. The most curious are those 

 relating to the composition of urine. He says : " Taking into 

 " account that there are many thousand persons who come to 

 " London during the day, but sleep without (and are not enumerated 

 " as living within) the metropolitan districts, and deposit their fluid 

 " excretion in town ; also many thousands of casual visitors ; taking 

 " further into account the rapid increase of London, we are justified, 

 " I think, in assuming that the population of London excretes an 

 "•amount of urine and valuable ingredients equal to that of two 

 " million adults or middle-aged males." 



Table XIX. gives the amount and value of the fluid void- 

 ings of the population of London, which, calculated as 2,000,000 

 adults, makes per day : — 



Urine, 650,000 gallons, or 2,901 tons, 176 gallons. 



Ammonia from urea, 36 tons at £60 per ton 5 value, £2,160. 



Ammonia from its salts, ^ "1 



Ammonia from uric acid, I ^ „ lom. 



Ammonia from creatinine, j vah £174. 



Ammonia from other nitrogenous matters, j 



Phosphoric acid, 6.2 tons — £86 i6s. 



Sulphuric acid, 4 tons — £37 6s. 



Chloride of sodium, 26 tons — £122 16s. 



Potash, 7.3 tons — £233 12s. 



Lime and magnesia, 1,714 lbs.— 17s. lod. 



Total urine, 2,901 tons, 176 gallons. And in this : 



Total solids, 84 Ions, or one ton of solids in 34.5 tons of urine. 



Total value, £2,832. 



