592 SELECTIONS FROM ADDRESSES. 



satisfied that he needs no* gold mine, if he could transform 

 these elements into marketable products. 



That wonderful power in vegetable physiology by which 

 each plant elects the matter, in quantity and kind, which is 

 essential to its existence, cannot now be dwelt upon. The 

 still more curious fact that each part of a plant has this power, 

 is worth an illustration. An early experiment of Mr. Tesch- 

 macher on this point, is very interesting and instructive. He 

 knew by many analyses that the grain of wheat had a large 

 proportionate amount of phosphorus, the stalk or straw none. 

 He made a rich compost of mould and manures, from which 

 the phosphates had been carefully eliminated, and divided this 

 into two portions, into one of which the theoretically required 

 proportion or phosphorus was added. The seed wheat was 

 sown in each, and each crop grew with strength and luxuri- 

 ance. When it had arrived at that point where fructification 

 should commence, that process was never set up in the crop 

 from which the phosphoric elements were omitted, but went 

 on to an entire grain in the other. Crops of wheat with lim- 

 ber stalks, incapable of bearing up the heads have been also 

 grown, or rather started, in peaty soils, where no proper pro- 

 portion of silex or flint to stiffen the barrel existed, as well as 

 experimentally in preparations in which entirely organic soils 

 were used. 



I deem these illustrations so essential in fixing the truth of 

 modern chemistry, that I know I shall be pardoned for adduc- 

 ing a few more instances. Since the mysterious failure of the 

 potato crop, it is well known that one of the best substitutes 

 has been found in the southern sweet potato, or yam. Our 

 markets receive vast supplies of this root from Virginia, and 

 indeed its cultivation as far north as Long Island has not 

 proved difficult. The impetus w^hich this demand gave to it, 

 at once called out the energies of the southern planter to in- 

 crease his crop. It was well known that its best soil was the 

 cow-penned tracts where cattle had been kept together. The 

 farmer naturally inferred that cow manure was the triie article 

 to dress his soil with, but to his surprise and disappointment 

 this preparation proved all in vain. No crop followed, and no 

 observation of his, enabling him to guess the reason or mend 

 the difficulty, he had only to yield in despair of a remedy. 



