VITAL PRINCIPLE. 
141 
“Oh Lord, how manifold are thy works, in wisdom hast thou 
made them all !” You are nourished by the same elements as 
the grass that perisheth ; the flowers have a much more refined 
corporeal substance than belongs to you ; and yet how much 
more precious are you in the sight of the Almighty than the 
vegetable creation. 
Do you ask, why you are of more value “ than the lilies of 
the field,” or than “many sparrows?” It is the very principle 
within you which enables you to make this inquiry, that renders 
you thus precious ; it is your soul that raises you above the in- 
animate and brute creation. Your body is but sister to the 
worm, and noxious weed ; but your soul may aspire to the fel- 
lowship of angels, and to be an inhabitant of heaven. Take not 
then your chief thought for the perishable part, but seek to ren- 
der the soul worthy of its high destiny. 
LECTURE XIX. 
VITAL PRINCIPLE. 
We have now, according to our method of arrangement, con- 
sidered the anatomy of the vegetable in connexion with its phys- 
iology : that is, when treating upon each particular organ, we 
have remarked upon its uses in the life and growth of the 
whole plant. We have treated of the germination of the seed, 
the minute vessels which constitute the vegetable fabric, with 
the fluids which circulate through these vessels ; we have, as it 
were, gathered these vessels together and considered them as 
constituting in various ways, three essential parts of woody 
plants, the bark, wood, and pith. We have inquired into the 
manner in which these separate parts are formed, and observed 
the great distinction in the growtli of the stems of monocotyle- 
donous and dicotyledonous plants. 
Yet although we have seen how plants grow, it is no easy 
thing to explain how they live. The great principle which ope- 
rates in organic life, appears not to have been laid open to the 
eye of man. But by a careful observation of facts, we can learn 
all that it is important for us to know in order to cultivate plants 
successfully ; their habits, food, and the causes of their diseases 
and death. 
The physician who spends a long and laborious life in the 
study of the human frame, can give only the result of observa- 
The wisdom of the Creator manifest in his works — Reflection — Limits to 
the study of the human frame — Retrospective view — 
