458 '•''Terra Culture'''' — Prof. Comstoch. [October, 



haying tlius far been followed principally as an art, and not studied 

 as a science, simply because our good motlier eartli from her bounti- 

 ful bosom lias fed her children without stint, imposing upon them 

 no need of invention, while an iron necessity has impelled to numer- 

 ous and great discoveries in other pursuits, and placed the mind, in 

 relation to them under the severest requisitions. In vegetable phy- 

 siology, we have learned but few things profitable, in a practical point 

 of view. We know when a seed is put into the ground the moisture 

 and heat cause it to swell; the pellicle that surrounds it is weaken- 

 ed and the embryo bursts through. We know further that vegetation 

 proceeds in two opposite directions, forming the radicle below, and 

 the plumicle above ; we say then that germination is the act by which 

 a seed, placed in the soil under favorable circumstances, develops it- 

 self, in order to give birth to a plant of the same kind as that whence 

 it sprang: that a seed to develop itself and form a vegetable, it is not 

 only necessary that it should be placed in the soil, and that the soil 

 should contain the Jiumvs, and mineral substances required for the 

 nutrition of the plant, but there must also be a concurrence of cer- 

 tain atmospheric influences, that perform an important part in the 

 phenomena of vegetation ; that these atmospheric influences or 

 agents are heat, moisture, air and light. 



And after a few facts of this kind which have been learned by ob- 

 servation, and which were doubtless known and understood by Adam 

 in the garden, the whole story ends. 



At this point hundreds of false theories, and unfounded practices 

 have sprung up, and others again are constantly taking root upon 

 these like the mistletoe, and are propagated from father to son, from 

 generation to generation. As in other sciences so in Agriculture 

 there must be one uniform course, from which there can be no devi- 

 ation. The first step must bring together and verify numerous facts ; 

 and when these have been satisfactorily established, to compare them 

 with each other, and from their agreement or disagreement, to de- 

 duce principles. 



Isolated facts are not sufficient to establish general principles. 

 It is necessary too that the facts collected should have been observed, 

 and verified, under the modifications and influences of difi'erent soils 

 and their fertilizers, the state of the atmosphere, the influence of 

 climate, and varieties of exposure before we can derive from them 

 such general principles as can be practically applied. If the agents 

 in vegetation were constantly the same and their action were uniform, 



