THE DAIRY. 513 



To show, however, that the " mineral theory " offers a grave 

 objection to the sale of milk, it is only necessary to state the 

 teachings of the following : — 



Analysis of Milk by Haidlen, 



Water 873* 



Butter 



30- 



Caseine 48-4 



Milk Sugar 43*9 



Phosphate of Lime 2-31 



Magnesia 42 



Iron -07 



Chloride of Potassium i -44 



Sodium and Soda '66 



i,ooo-oo 

 One hundred gallons of milk weigh about 1,000 pounds ; there- 

 fore, each hundred gallons remove from the farm 2*3 1 pounds of 

 phosphate of lime, and i'44 pounds of chloride of potassium. For 

 our present purposes the other constituents of the milk may be 

 disregarded, as being less in quantity and comparatively unimpor- 

 tant. Ten cows of good average quality will produce perhaps 

 5,000 gallons of milk per annum, and the sale of their milk will 

 remove from the farm ii5'5 pounds of phosphate of lime, and 72 

 pounds of chloride of potassium. 



It is true that these amounts seem trifling, when compared with 

 the immense quantities of both of these elements that all fertile 

 soils contain ; but it must not be forgotten that of the very large 

 content of mineral food developed by a searching analysis of the 

 soil, only a slight proportion is yearly made available for the uses 

 of the plant, and that the whole quantity removed is taken from 

 this available stock. If the restoration by natural processes is 

 sufficiently active to make up for the removal, and in many cases 

 no doubt it would be, practical farming need take no cognizance 

 of the loss. But on lands where yearly manuring is necessary for 

 the production of satisfactory crops, there is no doubt that even 

 this slight removal would in many instances tend, sooner or later, 

 to the impoverishment of the land. As before stated, however, 

 the threatened impoverishment is now so remote, and the means 



