ROOTS. 183 



in summer, the beet yielded from 3h to 4 per cent, of sugar ; 

 but in October, after the commencement of frost, it gave 

 only syrup arid saltpetre, and no crystalizable sugar. When 

 used for this purpose, the residuum of the pulp, after ex- 

 pressing the juice, is given to cattle. When wilted, the 

 leaves are also fed to them, but caution, and the use of dry 

 food in connection, is necessary to prevent their scouring. 

 What are not thus used, are plowed in for manure. The 

 beet is also distilled arid yields about half the product of 

 potatoes. 



NOTE. 



On the following pages, I append the table of nutritive 

 equivalents of food, compiled by Boussingault, as a conve- 

 nient reference, though not entirely reliable in all cases. For 

 it will be seen, from what has before been said, that the par- 

 ticular plants, vary, not only according to the season and 

 soil, but frequently also, according to the particular variety, 

 subject to analysis. He says : "In the following table, to 

 the numbers assigned by the theory, I have added those of 

 the whole, which I find in the entire series of observations 

 that have come to my knowledge. I have also given the 

 standard quantity of water, and the quantity of azote, con- 

 tained in each species of food. When the theoretical equi- 

 valents do not differ too widely from those supplied by direct 

 observation, I believe that they ought to be preferred. The 

 details of my experiments, and the precautions needful in 

 entering on, and carrying them through, must have satisfied 

 every one of the difficulties attending their conduct ; yet all 

 allow how little these have been attentively contemplated, 

 and what slender measures of precaution against error have 

 been taken. In my opinion, direct observation or experi- 

 ment is indispensable, but mainly, solely as a means of 

 checking, within rather wide limits, the results of chemical 

 analysis." 



