XXXIV ROYAL SOCIETY OF 
phoric acid. A crop of oats will take a little more nitrogen, considerably 
more potash and less phosphoric acid. These may serve as examples but 
every successive crop tends to deplete the remaining store of these im- 
portant elements and although the yearly reduction in quantity may be 
small compared with the total content, yet unless some means of restora- 
tion be provided, the richest soil eventually becomes poor. 
In a series of seven analyses of soils from the Northwest Provinces, 
made by Mr. Frank T. Shutt, Chemist of the Dominion Experimental 
Farms, they were found to contain an average of 18,000 lb. of nitrogen, 
15,580 lb. of potash and 6,700 lb. of phosphoric acid per acre, showing 
that the soils in the Canadian Northwest are much richer in these im- 
portant elements of plant food than good average soils in Europe. 
While nature at times seems lavish and, in some respects, almost 
prodigal, she is at the same time strictly economical. A substance may 
undergo a change in its character and thus elude our grasp, but nothing 
is ever lost. Decomposing masses of organic material undergo rapid 
changes in the laboratory of nature. Thus the nitrogenous matter they 
contain is converted largely into ammonia and nitric acid, which being 
volatile are disseminated through the atmosphere and brought down 
again to the earth to serve the purposes of plant growth by Ieee 
showers of rain. 
Experiments conducted at Rothamsted, England, and elsewhere, 
during the past few years, to determine the quantity of these nitro- 
genous compounds in the rainfall, have shown that about 3.84 lb. per 
acre are thus given annually to the soil during the growing season. 
During the past winter, Mr. Frank T. Shutt, Chemist of the 
Dominion Experimental Farms has determined the nitrogen compounds 
in snow. From his results he estimates that in 90 inches, the average 
snowfall at Ottawa for the past sixteen years, there would be approxi- 
mately 1 Ib. of nitrogen in the form of ammonia and nitrates and nitrites 
on each acre. 
The farmer who neglects his barn-yard manure and allows its valu- 
able constituents to be partly dissipated by excessive fermentation, loses 
thus so much of his capital, but the atmosphere holds what has been 
“wasted, and refreshing showers dissolve this gaseous material and bring 
it a earth again in the very best condition for assimilation by plants. 
‘as the careless farmer unwittingly becomes more or less a publie 
benefactor, and while he loses a large part of the nitrogen taken from his 
oil, the material is partially restored to earth in the rainfall elsewhere. 
N: nn has also admirable provisions for restraining waste. In all 
arable S04). the quantity of plant food which is soluble and immediately 
