180 THE SUGAR BEET. 



The following will show that the volume of these 

 gases varies considerably: — 



Mehay has also made many interesting experiments 

 with a view to ascertain if there exists any proportion 

 between the density of the juice and the entire root. 

 He found none, but concluded that a beet having a 

 high density and but little ash would yield a variety 

 superior to what had heretofore existed. Of late years 

 Dervaux has adopted, on his farm in France, a method 

 also based on the density, biit not having the disadvan- 

 tage of the above, he having proven some years previous 

 that a cylindrical piece taken from the root in a direc- 

 tion perpendicular to its axis has a density proportional 

 to the entire root, at an approximation sufficient to ren- 

 der errors committed of secondary importance. 



This being the case, the roots are chosen in the field 

 by exterior signs alone. The.'^e are sorted by the appli- 

 cation of Dervaux's idea. As may be imagined, here 

 we can operate in small vases containing from 200 to 

 300 grammes of salt and water, with as many hands 

 as vases, and consequently as rapidly as desired. 



The advantages of this over the ordinary methods 

 previously mentioned, are that the roots need not be 

 cleaned nor the leaves removed, nor is it necessary to 



