SUPPLEMENT. 43 



It is no doubt most convenient to refer for an answer to 

 Germany and France, and notice the conditions of the lands 

 engaged in tlie beet sugar cultivation for generations. We 

 shall find that the yield of good sugar-beets is not diminishing, 

 that the beet sugar industry in fact is continually growing — (lias- 

 increased in Germany within the last fifteen years threefold) — 

 and instead of reducing the general farm products, in conse- 

 quence of engaging so large an area in the sugar-beet cultiva- 

 tion, we know from statistical reports that they exceed in value 

 the farm products of previous periods. High farming based on 

 rational principles has taken the lead ; to increase the fertility 

 of the soil has been the aim ; advantageous systems of rotation 

 have been introduced and the effects of special manures have 

 been subjected to close study. Science has made itself famil- 

 iar with common farm routine, and an enterprising farming 

 community has listened to its advice. Two facts are quite evi- 

 dent to every intelligent farmer : first, that a certain chemical 

 and physical condition of the soil is required to secure by the 

 crops raised a satisfactory compensation for labor and expenses 

 incurred in its cultivation ; and, secondly, that the plants we 

 cultivate differ in their requirements in both directions. The 

 mineral constituents needed for the support of any one kind of 

 plant will be sooner or later exhausted, for nature as a general 

 rule does not change the mineral compounds required for the 

 maintenance of a forced vegetation into a fit state for assimila- 

 tion so rapidly as most of our farm crops, and the sugar-beet 

 in particular, require. Fortunately for us the disintegrating 

 surface of our globe has been for ages subjected to a leaching 

 process, and its products are daily more and more opened to us 

 in the form of saline deposits of every description ; the accu- 

 mulated results of animal and vegetable life of past generations 

 are brought back to us in the form of guano and phosphates of 

 varying character, while chemistry has taught us how to assist 

 nature in its preparation of plant-food. The physical condi- 

 tions of the soil, however favorable they may have been, will 

 suffer, if year after year subjected to the same or a similar treat- 

 ment for the cultivation of one and tiie same plant ; diversity 

 in its mechanical treatment and change of seasons for such 

 treatment cannot otherwise but affect favorably its mechanical 

 condition and its chemical disintegration, promoting thereby its 



