156 BULLETIN OF THE BUSSEY INSTITUTION. 
farmers near Boston, that night-soil is a “ forcing” manure that soon 
‘* exhausts the land” to which it is applied. The long horse-manure, 
on the contrary, from the stables of that city, which is a mixture of 
dung with much straw that has served for bedding the animals, has 
always been held in high esteem by the farmers of the locality, in 
spite of the fact that the dung almost always undergoes fermentation 
before it is removed from the cellars of the stables, and must, conse- 
quently, have lost much of the nitrogen that was originally contained 
in it. For this ill-kept horse-manure the farmers are glad to pay the 
stable-keepers a considerable price in the first instance, and they are 
afterwards at the expense of transporting the bulky material some miles 
into the country, and are often put to the further cost of rehand- 
ling it at the farm. But for night-soil there is no quick market. By 
far the larger part of that produced in the city finds its way to the 
sea. Even in the times when water-closets were unknown, and the 
present system of discharging the filth of the city into its sewers had 
no existence, thousands of tons of night-soil were shot overboard 
from the city wharves and bridges, in order to avoid the expense of 
hauling it four or five miles to the farm land. 
But horse-manure is a potassic manure, while night-soil, whether 
fresh or stale, is not. The hay and oats eaten by the horses of an 
American city and the straw upon which the horses sleep all contain 
a much larger proportion of potash than do the bread and meat and 
vegetables that serve as human food. The more thoroughly, more- 
over, the original horse-manure has been wasted by fermentation, so 
much the richer in potash will be the matters that are left. But 
night-soil when fresh is rich in nitrogen, and when old it is a phos- 
phatic manure charged with more or less nitrogen ; the proportion 
of potash contained in it at any time is, comparatively speaking, small. 
Hence upon soils that lack potash, night-soil can produce only a tem- 
porary useful effect. The active nitrogen contained in it would natu- 
rally ‘‘force” the soil to give up to the first crops what little available 
potash it might possess, and the land would thus be “ exhausted.” * 
It is a noteworthy fact that some of the farmers in the vicinity of 
Boston who habitually make use of night-soil are accustomed to mix 
with it the strawy horse-manure just mentioned, obtained from stables 
* Compare the results obtained by the use of sulphate of ammonia and by that 
of fish-scrap on Sections B and BB, squares 3 and 8, during the three years. 
