77 



ON THE ROOTS OF PLANTS. 



To give life and motion to the seeds of plants, 

 a certain portion of water, and of oxygene or 

 vital air, and a degree of heat of about 5(f Fa- 

 renheit, is necessary. A seed being placed in 

 the earth under these circumstances, it imme- 

 diately absorbs moisture, and gradually swells 

 to the extent of its shell, or skin, when the 

 radicle, or first root, protrudes itself, and in 

 whatever position the seed be placed, assumes 

 a perpendicular direction, and gradually makes 

 its way downwards into the soil ; and the germen 

 also assumes a perpendicular position, and grows 

 upwards. A great number of experiments have 

 been made to ascertain the peculiar principles, 

 which influence and give direction to the first 

 rudiments of plants, and many are recited by 

 Sir H. Davy ; but whether the first inclinations 

 of a plant be considered as instinctive, or whe- 

 ther, by the influence of any peculiar principle, 

 the root is impelled forward into the earth, is 

 of trifling importance to the practical agricul- 

 turist : and whether it may be accounted for on 

 the principles of gravitation, or attraction, it is 



