104 CHYMISTRY APPLIED TO AGRICULTURE. 



forth buds and stalks in the spring ; a branch of a vine 

 introduced during the winter into a hot-house, vegetated 

 as it would have done in the spring, whilst that portion of 

 it which remained exposed to the cold experienced no 

 change. Plants that have been browsed in autumn, do 

 not put forth so early, nor with so much strength as those 

 of which the roots, and the parts immediately surmounting 

 them, have been preserved by mowing. 



All agriculturists have observed, that young trees trans- 

 planted in the spring appear to flourish for three or four 

 months, and then die; if when taken up they have ex- 

 amined their roots, they have almost invariably found 

 that they presented no appearance of having increased ; 

 which proves that vegetation is carried on in the spring 

 by the nourishment provided, and deposited in plants be- 

 fore the fall of the leaves. 



The difference which exists in the vegetation of the 

 same branch, one end of which is placed in the earth, 

 and the other rising above it, must strike every observer. 

 The part which is planted in the soil, sends forth roots, 

 whilst that which rises into the air produces leaves ; and 

 if any part of the root be uncovered, so as to come in 

 contact with the air, it produces stalks and leaves ; whilst 

 that which remains beneath the soil continues to grow as 

 the root of them. All parts of plants then are organ- 

 ized by their growth in such a manner, as shall enable 

 them, most conveniently, to imbibe at the same time their 

 nourishment from the soil and from the atmosphere. 



It is in the power of art to influence the flow of the 

 sap, nearly at will. When the nourishment afforded by 

 the earth is too abundant, it is but imperfectly digested, 

 and is exclusively employed in the growth of the plants; 

 a tree in this case produces neither flowers nor fruit, but 

 expends all its strength in leaves and wood. To remedy 

 this superabundance of sap, some of the roots may be 

 separated ; or what is still better, incisions may be made 

 in the bark of the tree to cause the escape of a portion of 

 the sap. 



If it be wished to facilitate the growth of the fruit, a 

 portion of the branches may be pruned, and part of the 

 fruit be plucked off; in this way a greater quantity of 

 sap may be supplied to the fruit that remains ; tight 

 ligatures upon the branches, and incisions surrounding 

 them through the whole thickness of the bark, produce 



