RELATIONS OF FEEDING TO FERTILITY. 93 



left on the farm. Of course there comes in the question of skim- 

 milk which is left on the farm. That skim-milk is fed to the pigs 

 and fat swine, and that carries off but a very small amount. So 

 that the system of butter making and the fattening of pigs for 

 market, carried on together, as ihey usually are, leave upon the 

 farm the greater part of the elements of fertility which have been 

 taken from the soil by the crops, to be returned to the soil and aid 

 in producing succeeding crops. 



Cheese, being of a different nature from butter, carries off more 

 of the fertilizing material ; yet the showing with cheese is far ahead 

 of the sale of raw products. For instance, a ton of beans or a ton 

 of peas would carry off nearly as much of the elements of fertility 

 as will a ton of cheese, and yet the ton of cheese is worth far more 

 money than is the ton of peas. With milk the showing is just about 

 the same as it is with cheese. 



A ton of unwashed wool, another of our farm products, worth at 

 the present time five hundred dollars or a little more, carries with it 

 onl}' one hundred and eight pounds of nitrogen, eight pounds of 

 phosphoric acid and one hundred and fort^'-nine pounds of potash ; 

 carrying off a large amount of potash, you see, but onl}' a small 

 amount of these other materials in proportion to its market value. 



This, then, is something of an indication of the practical working 

 of the feeding out of these products as compared with the selling of 

 them in the market in the raw form. 



Question. I would like to know what it would cost to replace 

 the fertilizing material that there is in a ton of English hay by 

 purchasing commercial fertilizei's. 



Sec. Gilbert. That is the point that I was proposing to take up 

 if you do not care to pursue this an^- further. I think there was 

 something said last spring when I was here at a meeting of this club, 

 in regard to the values of manures, but I will repeat it. 



A manure is valuable for the amount of nitrogen, phosphoric acid 

 and potash thei-e is in it. These materials are what give value to 

 the fertilizer, whether commercial or from the barn. So if we 

 know what a pound of nitrogen is worth we can reckon and deter- 

 mine what a manure costs. In commercial fertilizers this available 

 material, available nitrogen, phosphoric acid and potash, has a 

 market value, which is just as plainly fixed as the market value of 

 a bushel of salt in the market in your own cit}- ; and it sells for its 

 market value, just the same as an}' other commodity sells for its 



