CHEMICAL FERTILIZERS. 119 



mulas. It is similar to one which might be made by a mechanic, 

 that to cover the side of a building thirty feet long and fifteen feet 

 high, it will require four hundred and fifty square feet of boards. 

 It would perhaps be preposterous to say, from our limited data, 

 that the statement of the formulas in results can compare in exact- 

 ness with that of the mechanic, but a few facts in the form of 

 figures will show that in a few years it might approximate it very 

 closely." 



Instead of this illustration in mechanics, let us try the following : 

 I have a cow that gives daily, on ordinary feed, eight quarts of 

 milk, which may be called her natural yield. I wish to make her 

 give sixteen quarts per day, eight quarts more than her natural 

 yield, and to effect this I give her the constituent elements of 

 eight quarts of milk, and to be exact in quantity, I give her to 

 drink eight quarts of her own milk. Why should she not give six- 

 teen quarts the next day ? 



Some of the reasons why we should not expect the application 

 to the soil of the elements of fifty bushels of corn, to add fifty 

 bushels of corn to the crop, readily occur to us all. We may esti- 

 mate ten inches of soil upon an acre, as I have said, to weigh a 

 thousand tons, or two million pounds. We apply to this, three 

 hundred or four hundred pounds of a fertilizer. It is manifestly 

 impossible so to incorporate this small amount with the soil, that 

 the roots of the corn shall find just as much more of each element 

 as we have added, and what the plant does not find is useless to it. 

 Again, the condition of the soil as respects drainage and pulveriza. 

 tion, and its density, are essential. In a soil filled with stagnant 

 water nothing but water-grass, and mud turtles can thrive, how- 

 ever fertile it may seem to the chemist, and a hard, compact sur- 

 face, like a roadway, however rich, can produce nothing. 



*We are told to apply nitrogen, potash, and phosphoric acid, but 

 these are not articles of commerce, which a farmer is expected to 

 buy under those names at a reasonable price. The pamphlet re- 

 ferred to in the advertisement tells us in what form we can obtain 

 these elements, as follows : 



" Commercial Sources of Nitrogen, Potash, and Phosphoric 

 Acid. Nitrogen. — From sulphate ammonia, Peruvian guano, dried 

 blood, common saltpetre, nitrate soda, fish guano. Potash. — 

 From muriate potash, sulphate potash, wood ashes, common 

 saltpetre, carbonate potash. Phosphoric Acid. — From dissolved 



