116 MASSACHUSETTS HORTICULTURAL SOCIETY. 



of earth, from which the most persevering lixiviation with pure 

 water, or water containing carbonic acid, will not extract even the 

 one hundredth part of the phosphoric acid and nitrogen, nor the 

 fiftieth part of the potash and silicic acid, which the plant has 

 drawn from the soil," * And, what seems conclusive on this point, 

 he says that if plants did receive the food from a solution which 

 might change its place in the soil, the principle nutritive substances 

 must long ago have run away in the brooks and rivers. " For 

 thousands of years, all fields have been exposed to the lixiviating 

 action of rain water without losing their powers of fertility. In 

 all parts of the earth, where man for the first time draws fufrows 

 with the plow, he finds the arable crust, or top layer of the field, 

 richer and more fertile than the subsoil."! And although he ad- 

 mits that plants will grow in watery solutions of mineral elements, 

 yet he says they bear no comparison with plants grown in a fertile 

 soil. 



Prof. Johnson, of Yale College, examining the statement of 

 Liebig and others, adopts the conclusion that water is capable of 

 dissolving from the soil all the substances that it contains which 

 serve as the food of plants, though I think a careful reading of his 

 discussion of the point leaves the question in great doubt. J 



In another part of his treatise, he sa3^s the roots " supply the 

 plant with large quantities of water when the soil is so dry that it 

 has no visible moisture." § We may add that in California it is 

 not unusual to plant and harvest crops of grain without a drop of 

 rain in the whole season. And in the last page of his book. Prof. 

 Johnson as nearly gives up his position as could well be done, 

 without an absolute surrender. He says in italics, " Those bodies 

 which are most rare and precious to the growing plant, are by the 

 soil converted into, and retained in, a condition not of absolute, 

 but of relative insolubility, and are kept available to the plant by 

 the continual circulation in the soil of the more abundant saline 

 matters." || 



Enough has been said, in these mere suggestions of the embar- 

 rassments attending the investigation of the subject of chemical 

 fertilizers, to render us cautious in our examination of the claims 

 of any supposed new theory of chemical plant feeding. The at- 

 tention of the civilized world has for a generation, at least, been 



* Natural Laws of Husbandry, page 109. flbid, p. 108. > 



X How Crops Feed, p. 316. § Ibid, p. 212. || Ibid, p. 375. 



