3M HANDY-BOOK OF HUSBANDRY. 



seed, and the whole is harvested and removed from the land. 

 This branch of the question is thoroughly discussed in a paper by 

 Dr. Voelcker, vi^hich is published herewith ; but it seems probable 

 after all, — so great is the manurial influence of clover, — that it 

 must actually absorb and appropriate into its own substance the 

 nitrogen of the atmosphere, though there is no proof, and as yet 

 no means of proving that this process actually takes place. 



The paper of Dr. Voelcker referred to above, is copied entire 

 fj^om the " Journal of the Royal Agricultural Society of England." 



(This paper is so thoroughly scientific and valuable, and is so 

 logically arranged from beginning to end, that it would be unfair 

 to its author to attempt any condensation of it. Every farmer 

 who cares to consider the reasons for what he does, who realizes 

 the importance of understanding nature's modes of operations, will 

 find its careful perusal to be of the greatest value. Those who, 

 from lack of information or lack of time, desire only to know the 

 conclusions to which it leads, will find them conclusively stated 

 in the summary with which it closes.) 



"on the causes of the benefits of clover as a prepara- 

 tory CROP FOR WHEAT. BY DR. AUGUSTUS VOELCKER. 



" Agricultural chemists inform us that, in order to maintain the 

 productive powers of the land unimpaired, we must restore to it 

 the phosphoric acid, potash, nitrogen, and other substances which 

 enter into the composition of our farm crops ; the constant re- 

 moval of organic and inorganic soil-constituents by the crops usu- 

 ally sold off the farm, leading, as is well known, to the more or less 

 rapid deterioration and gradual exhaustion of the land. Even the 

 best wheat soils of this and other countries become more and 

 more impoverished, and sustain a loss of wheat-yielding powej, 

 when corn crops are grown in too rapid succession without 

 manure. Hence the universal practice of manuring, and that, 

 also, of consuming oil-cake, corn, and similar purchased food on 

 land naturally poor, or partially exhausted by previous cropping. 



" While, however, it holds good, as a general rule, that no soil 

 can be cropped for any length of time without gradually becoming 

 more and more infertile, if no manure be applied to it, or if the 

 fertilizing elements removed by the crops grown thereon be not, 



