HISTORY OP BC^ANY, 
22i 
the first of the Greek writers who composed a treatise on the proper- 
ties of plants! A disciple of his, Empedocles, seemed to have some 
correct ideas of vegetable physiology. He called the seeds the eggs 
of plants ; the roots, their heads and mouths ; and considered that 
the two sexes were combined in the same individual. 
' Several men of the name of Hippocrates- wrote upon the medici- 
nal properties of plants ; but their descriptions, being destitute of 
system, are vague, and cannot be applied to plants with any degree 
of certainty. 
Aristotle, perceiving that the course taken by preceding philoso- 
phers had not conducted them to the true knowledge of things, 
partially renounced their false ideas, and rested more upon obser- 
vation and experience. In his researches, he was favoured by Al- 
exander, of whom he had been the preceptor. That conqueror, in 
the midst of pride, and the fury of passion, still possessed the love 
of true glory, and a desire that his conquests might serve to promote 
the improvement of the human mind ; he allowed to Aristotle, in the 
prosecution of his scientific inquiries, every facility that wealth and 
power could bestow. 
Aristotle believed, that in nature there was a regular progress 
from inorganized matter upwards to man, and from man upwards 
to the Deity ; that beings were connected together b)^ certain affini- 
ties, composing an immense chain, of which the finks were afi con- 
nected. But, 
"Lives the man whose universal eye 
Has swept at onee the unbounded scheme of things? 
Has any seen 
The mighty chain of beings, lessening down 
From infinite perfection, to the brink 
Of dreary notiiing, desolate abyss?" 
This idea of a regular chain of beings, presenting itself with such 
grandeur and simplicity, has had many admirers ; but facts do not 
seem to correspond with this theory. In the vegetable kingdom we 
should find it impossible to trace a regular gradation from the oak 
to a moss (if we were to make these the extremes of the chain of 
vegetable substances,) and say exactly in what part of the scale each 
family of plants should be placed; it would rather seem, in many 
cases, as if the links of the chain had been broken or disunited. 
Aristotle considered plants as intermediate between inorganized 
matter and animals. Plants, he said, are not distinguished from an- 
imals in being destitute of the seat of life, the heart^ because of this 
the reptiles and inferior orders of animals are also destitute ; but 
plants have no consciousness of themselves, or organs of sense to 
know what is out of themselves; animals possess these faculties; 
therefore, Aristotle says, they are different. We think it would have 
been difficult for him to have discovered any evidence of conscious- 
ness in the sponge, or any marks by which it might appear that this 
animal substance (for such it is thought to be) has the knowledge of 
any thing external to itself However great may be the veneration 
entertained for the opinions of Aristotle, we believe his distinction 
between plants and aninaals wifi at this time find no supporters^ 
This philosopher published his works on natural history about 384 
years before Christ. 
Theophrastus, the friend and pupil of Aristotle, published a great 
number of learned works ; among others " A History of Plants," and 
^' The Causes of Vegetation." He treated separately of aquatic 
Empedocles— Hippocrates— Aristotle— Various opinions of Aristotle— Thecphraetuji. 
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