INTRODUCTION. 



It is specially gratifying to have been chosen b}- the 

 author to give an introduction to this book, since for many 

 years past we have had numerous opportunities of appreciat- 

 ing the value and interest of the works of M. de Sornay. 



The family of the Leguminosce is one of the most im- 

 portant in the plant kingdom, not only on account ot the 

 diversity of its species, but because of the practical value 

 of its products, either as food, or in trade, or from a 

 farming point of view. 



The leguminous plant, in fact, is one of which the nature 

 and physiology are most complex. Its peculiar property 

 of fixing atmospheric nitrogen has been the cause of a 

 number of controversies, and the study of it has aroused 

 the interest of numerous scientists, who, at any rate at first, 

 were bv no means in agreement. To-day it is practically 

 universally accepted that this plant does possess the property 

 of fixing atmospheric nitrogen, but a Scotch scientist has 

 endeavoured to confute the idea of this faculty being confined 

 exclusively to the Leguminosce. He has brought forward 

 a number of experiments and arguments aiming at showing 

 that the Leguminosce only share, although in a more marked 

 degree, the faculty common to all plants of absorbing 

 atmospheric nitrogen l)y means of organs situated on their 

 leaves. 



However that may be, the point of greatest interest to 

 us is to acquire a better knowledge of the plant, not from 

 the piivsiological point of view (these principles to-day being 

 sufficientlv well established), but rather from the economic, 

 farming, and general agricultural point of view. 



The importance of this class of crop and the advan- 

 tages to be derived from it are well known, and all wlio 



