CHEMISTRY OF THE CROP. 



239 



home or abroad, Has been investigated and analyzed, either 

 by our own or continental chemists, so that their compo- 

 sition and their soil requirements are now well known to 

 us. The proportion of straw or stem to seed or grain is 

 on the average about 3 to 2 ; and the average percentage 

 of ash (inorganic matter) in each may be taken at from 

 2 -5 to 3 per cent, in the seed the smaller varieties contain- 

 ing the largest proportion, and from 5 to 7 per cent, in 

 the straw. The following analyses, by Messrs. Way and 

 Ogston, give us the percentage composition of their mineral 

 or inorganic matter: 1 



These results are the mean of six analyses of beans in 

 ordinary cultivation the Heligoland and Mazagan varie- 

 ties and of four analyses of the bean straw, by which 

 we also find that the average proportion of water in the 

 bean is about 14 per cent., and in the straw about 10 per 

 cent. Assuming, therefore, that a fair crop of beans 

 would produce 32 bushels, weighing 66 Ibs. per bushel, we 

 should find from the foregoing figures that it had removed 

 from the soil something like the following amount of 

 mineral constituents, which must be restored to the soil 

 in some shape or another, if we wish to sustain its normal 

 fertility or condition : 



1 Roy. Agri. Soc. Jour., vol. ix. p. 152. 



