436 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



those apparent in a soil that had only been surface plowed, being 

 sometimes too wet and sometimes too dry. The speaker believed 

 that a soi properly drained and sub-soiled had never been known 

 to suffer from drouth ; and this was explained simply on the 

 ground that the atmosphere, if freely admitted into the soil, 

 could always supply moisture, and furnish the necessary amount 

 of ammonia and carbonic acid, to render the water of the soif 

 more capable of dissolving the inorganic compounds required to 

 sustain the plants ; not only supplying the progressed elements, 

 but assisting in the operation. 



The life principle of plants was also a most important agent 

 in the general law of progression. Thus, as stated in a former 

 lecture, a tumblerful of water containing soil, might be made to 

 exemplify the process, if it contained the fertilizing gases. The 

 presence of a root in this tumbler, will cause the water to dis- 

 solve a much greater portion of inorganic matter than would be 

 taken up by a like quantity of water, in which there was no root. 



But before entering upon the subject on which he had intended 

 to speak, he would draw attention to an experiment which had 

 been made by the Rev. Mr. Smith, of Lois Weedon. This gen- 

 tleman found that if he planted alternate strips of wheat, so that 

 spaces amounting in all to one-half an acre should be completely 

 covered, the half acre so occupied would produce more wheat 

 than would the whole acre planted in the ordinary manner. He 

 therefore planted alternate rows of wheat (leaving the interven- 

 ing strips bare), and using half the quantity of seed which he 

 would have previously required to plant an acre ; the intervening 

 spaces being thoroughly disintegrated. To his surprise he found 

 that though he had applied no manure of any kind, he had a 

 much larger crop than if he had sown in the usual way. The 

 next year he repeated the experiment, and continued to do so for 

 fourteen years, merely alternating the relative position of the 

 wheat and bare strips, and his crop went on gradually increasing 

 to 36, and finally 48 bushels. He, however, does not recommend 

 that the wheat should be planted without manure, but believes 

 that if his field had been manured the yield would have been 

 greater still. By permitting the roots of the plant to pass 

 through those parts of the ground Avhere nothing was planted, 

 and where the atmosphere was permitted to permeate, thus giving 

 full power to the active principle to be freely developed : and by 

 changing the relative position of the rows from year to year, he 

 made way for the disintegration of a quantity of new inorganic 



