CHEMICAL FERTILIZERS. 143 



ing of my resources, the Professor sa3S " provide the whole." 

 This process seems to be about what Prof. Stockbridge has pat- 

 ented. He does not tell us how much we have on hand or what 

 we are to expect from the operations of nature. The only thing 

 new in this patent seems to be its absurdity. Mr. Fuller said he 

 should be sorry to feel that President Clark had fully endorsed 

 these formulas, for he considered him one of the foremost men of 

 the State in agricultural pursuits, and his experiments on the flow 

 of sap and the power of plant-growth had given him a just fame, 

 and greatly elevated his college. He feared that, whatever may 

 have been the motive of Prof. Stockbridge in patenting these for- 

 mulas, they would not increase the popularity of that institution. 

 The constituents of plants are organic and inorganic ; all that 

 will not consume are inorganic, and it is only these that we under- 

 take to supply. Some soils have a great excess of some constitu- 

 ent. In Hungary, it is said, there are soils from which alternate 

 crops of cotton and tobacco have been taken for centuries, without 

 exhausting them. Prof. Stockbridge's formulas for these crops 

 contain the same ingredients as for others, with the addition of 

 lime and magnesia. The growth depends not so much upon what 

 goes into the soil and what is taken out, as upon the substances 

 which enable the plants to appropriate what is nutritive in the 

 soil. These substances must have a certain form and condition 

 and relation to each other, to become available. The inorganic 

 constituents of plants are but from one to fourteen per cent, of the 

 whole — commonly about five per cent. — and the air furnishes all the 

 carbon and all the residue. Moisture, warmth, and air — heat and 

 ■ sunlight and chemical adaptations — are the conditions for develop- 

 ment. The physical condition of the soil — its pulverization and 

 exposure of parts — produce chemical changes, and are often very 

 essential to production. True art in agriculture appears to consist 

 in adopting proper means to make the most of what the soil con- 

 tains, and in enabling the elements of the soil to cooperate in as- 

 similating the food. Soils equally productive differ greatly in their 

 chemical composition. By an excess of any element you may 

 harm the plant. If, for example, there is too much of a soluble 

 salt in the soil, after a rain the plant will absorb so much that, in 

 case of hot weather following it, the evaporation from the leaves 

 will be more rapid than the assimilation, and a white crust or pow- 

 der is left on the surface and the plant sickens in consequence. 



