34 CHYMISTRY APPLIED TO AGRICULTURE. 



This explains in a natural manner the origin of a cus- 

 tom observed by all agriculturists, and of which all ac- 

 knowledge the advantage. When vegetables, such as 

 peas, beans, potatoes, and other roots are sowed in fur- 

 rows at equal distances from each other, the soil in the 

 intervals is hoed, or dug, with the utmost care, and thus 

 rendered light, soft, and permeable to the air, whilst at 

 the same time weeds, which would be hurtful to the culti- 

 vated plant by depriving them of nourishment afforded by 

 the ground, are destroyed ; and the soil rendered more fit 

 to receive the rain, and convey it to the roots. I do not 

 deny that these benefits are real, but I hold them to be 

 secondary, and subordinate to the advantage derived from 

 opening access to the air, and permitting it to deposit its 

 dews upon the roots, and upon the earth in contact with 

 them. 



I have uniformly observed the effect of this method to 

 be equally speedy and favorable in the cultivation of beet 

 roots, and I have never employed any other, to restore their 

 vegetation to its freshness when it becomes yellowish, and 

 drooping ; in three or four hours it will become of a beau- 

 tiful green, and the leaves spread themselves out, although 

 no rain may have fallen ; and this often when the soil had 

 not contained a single weed. I have observed the same 

 effect produced upon the other culinary roots. 



A custom which is universally practised in the south of 

 France, attracted my attention for a long time, without 

 my being able to account for it. In that country, where 

 it hardly ever rains during the summer, the foot of each 

 setting of the vine is laid bare by digging around it a cir- 

 cular trench, deep, and wide enough to contain uncovered 

 the stump, and the radicles proceeding from it ; and the 

 opening is speedily covered over by the leaves and branch- 

 es. It is evident that this method has no other advantage 

 than that of facilitating the access of the air to the roots, 

 that it may deposit there the dew with which it is more 

 abundantly charged than in cold climates; if it were not 

 thus, this practice would expose the vines to be dried up 

 by the scorching heat of the sun. 



All soils have not the same affinity for water, which arises 

 from their different degrees of tenuity, or the division of 

 their particles, and from the nature of the substances which 

 enter into their composition. In general, the more finely 

 the parts of a soil are divided, the better they absorb 

 water 



