63 



BIOLOGY OF PLANTS. 



means of supplying some other agency necessary to the action 

 of the vital functions. 



• It has been suggested, that there is produced, by the various 

 mineral ingredients of which soils are mostly composed, an 

 electrical effect, which facilitates the absorption of the food. 

 The soil, in connection with the living plant, is a galvanic 

 battery, not only acting directly upon the vital functions, but 

 also rapidly decomposing the soil itself 



4. The soil also serves as a sponge to retain the requisite 

 supply of water. It retains the caloric, and permits a free cir- 

 culation of air ; all of which it distributes according to the 

 wants of the plant. 



5. Finally, the soil serves to retain gasious proclucts, as 

 ammonia, which it yields up as the wants of the plant require. 



Such being the important agency of the soil, it is of the 

 highest practical interest to the farmer, to ascertain its cha- 

 racter ; for all soils do not perform these functions with the 

 same degree of perfection ; hence the farmer, before he casts 

 the seed into the earth, should inquire, whether the soil is. 

 fitted to discharge those duties, which the peculiar constitu- 

 tion of the expected crop requires ; and he should not hope 

 for a bountiful harvest, unless this condition of the vital pow- 

 er is supplied. Proper attention to the soil is one of the se- 

 crets of successful farming. It is from this belief that I have, 

 in future chapters, devoted so large apart of the present work 

 to its formation, composition and improvement. 



II. Food. The second condition required for the most 

 vigorous action of the vital principle, during the grov.th of 

 plants, is proper food. We have noticed the beautiful provi- 

 sion of nature, by which a supply of food is stored up in the 

 seed or bulb, for the support of the germ. This portion, how- 

 ever, is small, and when it is exhausted, food must be supplied 

 from some foreign source, from the atmosphere, the water, 

 and from the soil ; or the vital power, having nothing to act 

 upon it, and sustain it, will be destroyed. Hence proper nour- 



