On llic Food of rimils. 
539 
analysis of the aslics of a carofully-solected portion of favmyard 
inanuie, the result of which fully confirms the beautiful views of 
the author referred to : — 
Farmyard horse manure, two years old — East Creenwich : 
sample selected from the middle of the heap, and dried completely 
in the sun : — during the latter part of the incineration, ammonia 
was disenga<;ed, probably from the action of the moisture of the 
air on a cyanide — 
500 grs. produced of ash . . . 124 grains. 
20 grains gave, on analysis — 
Sulphate of putash 
Sol. chlorides, with trace r,f alhiilliir] 
carbonate . . . . j 
Earthy phosphates, ox. iron, &c. 
Carbonate of lime 
Siliceous scales .... 
In 100 parts, 
r 
■.3G 
0-8 
2 ' 
94 
14-7 
6 
•8 
34-0 
2 
•4 
12-0 
G 
32 -.f) 
20-0 100-0 
Every hundred pounds of dry dung placed on the land is thus 
seen to convey to it no less than 8 4 pounds of phosphates of lime 
and magnesia. 
As I have no intention of entering into the much-disputed 
question of the propriety of using this manure in its recent state, 
or after a certain amount of decomposition, it will only be neces- 
sary to remark that those who actually cause its complete desic- 
cation, as related by the Rev, Mr. Rham, in his interesting 
account of the agriculture of the Netherlands,* by no means 
destroy the whole, or even perhaps the greater part of its value, 
as the practice fully proves, although a large portion of what 
ammonia mav exist in it is dissipated and lost. 
A suggestion is to be found in Liebig's paper which deserves 
great attention ; he proposes to prevent the loss of ammonia 
during the fermentation of the urine in the tank in which it is 
collected by mixing with it some cheap mineral acid which would 
deprive it of volatility. In an experiment made in the course of the 
summer, I found that when fresh urine was mixed with oil of 
vitriol the decomposition of the urea went on as if no acid were 
present ; a peculiar odour was emitted during the change, not 
quite agreeable it is true, but infinitely less annoying than the 
mixture of ammoniacal gas and sulphuret of ammonium given oH" 
by putrefying urine. Two gallons of human urine produced 
enough ammonia to neutralise very nearly seven ounces by weight 
of oil of vitriol. 
* Journal of the Royal Agrieultuval Society, vol. ii. p. 43. 
