88 



OUR FARM CROPS. 



Boussingault estimates the relative proportion of grain 

 and straw as 1 to 2 - 631, and quotes, in support of the 

 probable accuracy of these figures, the results of the fol- 

 lowing experimenters: 



Thaer gives for 1' grain, 2* of straw. 



Podewils 



Berger 



Block 



Dierexen 



Schwerz 



2-857 



2-292 



3-03 



2-564 



2-272 



In the operation of analysis it has been found that 

 the grain of wheat contains, on the average, about 1'75 

 per cent, of ash, or inorganic matter (varying between 

 1*2 and 2 per cent.) ; that the straw contains, on the 

 average, about 4 per cent., but shows a much greater 

 amount of variation in the different varieties Piper's 

 thickset, for instance, giving 11 per cent, of ash; and that 

 the chaff contains a far higher proportion of inorganic 

 matter than either grain or straw, leaving no less than 

 from 7 per cent, to 16 per cent, of ash when tested in the 

 usual manner. The ash represents, of course, the mineral 

 constituents of the soil which the plant has abstracted for 

 the use of its several parts; which constituents have been 

 determined by our chemists to be as follows : 



1 The mean of several. 



2 Fromberg. 



3 Boussingault. 



