122 
BULLETIN OF THE NATURAL HISTORY SOCIETY. 
application of fertilizer in ordinary farm practice will yield; an 
acre of peas has been known to add to the soil 139 pounds of 
nitrogen. So it is always possible for the farmer to return to 
the soil the nitrogen which repeated cropping has removed. 
Of the second article I have named, there is an unlimited 
supply in the great areas of felspathic rocks to be found in New 
Brunswick. But though we know there are great quantities of 
potash salts in the crystalline rocks of the New Brunswick hills, 
we have not yet learned how to separate them, render them 
soluble, and so make them quickly available for stimulating 
vegetable growth. Hence, for supplies of this fertilizer, since 
wood ashes have become scarce, we are depending upon the 
ground slag that comes from ore-furnaces, on the deposits of 
potash salts in Chili and on “ Kanit,” which is the product of 
German mines, where potash is mixed with soda. These are all 
foreign, but we have a domestic source of potash in the ashes of 
sea-weeds which, in some countries, are largely burned for this 
product, and for producing other valuable chemical substances. 
Now, of the third substance I have mentioned, namely, phos- 
phorus, the world’s supply is not on so liberal a scale 
as that of the two preceding. The phosphate industry of Canada 
in the “ sixties ” was in quite a prosperous condition. Large 
quantities were taken from the great veins of phosphate of lime, 
mingled with other minerals, that are found in the Laurentian 
region of the Ottawa valley. At Buckingham station and other 
points on the railway line near Ottawa many tons of it were to 
be seen in those days at the railway stations, being prepared and 
packed for shipment to market. You will ask, What has become 
of that industry? Well, for the time it has vanished! This is 
due partly to the difficulty of mining this ore, partly to the large 
proportion of it that is insoluble in its crude condition, but 
chiefly to the discovery of other sources of supply of phosphate 
that are more immediately available, or contain a larger propor- 
tion of phosphates in a soluble form. 
One of these sources was opened up in the discovery of exten- 
sive deposits of the bones of vertebrate animals of a former age 
