1 00 GERMINATION. 



I humbly conceive therefore, that if the human understanding 

 can, in any case, flatter itself with obtaining in the natural world, a 

 glimpse of the immediate agency of Deity, it is in the contempla- 

 tion of this vital principle, which seems independent of material 

 organization, and an impulse of his own divine energy. 



CHAP. I. 



GERMINATION. 



GERMINATION is a term applied to that part of 

 vegetable physiology, which explains the process by 

 which a seed becomes a plant. 



For the terms applied to the various parts of a seed, see p. 59. 



When a seed is committed to the earth, under the 

 proper conditions of air, heat, and moisture, it first 

 swells by the fluids absorbed by its vessels. Accord- 

 ing to Dr. Thomson of Edinburgh, a chemical action 

 next takes place ; oxygen gas is absorbed, and carbonic 

 acid evolved; by this process, the carbon in the farina 

 of the lobes being diminished, and the oxygen increased 

 in proportion, it is, in part, converted into sugar. The 

 cotyledons thus prepared, convey nourishment through 

 vessels, fitted for the purpose, immediately to the em- 

 bryo or chick. Thus supplied with nourishment, the 

 chick sends its radicle downward, taking such root as 

 finally to be supplied with nourishment from the earth, 

 and its plume upward, to unfold itself into herbage. In 

 this process, the integuments of the seed are ruptur- 

 ed and presently decay. The radicle makes its ap- 

 pearance rather before the plume. 



Observation. The chemical action, mentioned above, is attend- 

 ed with an evolution of heat which results from the absorption of 

 oxygen 



The evolution of .sugar is precisely what takes place in malting-, 

 in which the seed is exposed in a warm place and moistened un- 

 til germination commences, when the process is stopped by drying 1 

 it.- It is then found to have become sweet, -.-d is used to impart 

 saccharine matter to beer. 



