LEAVES. 
67 
It is delightful, while gratifying our natural love of knowledge, 
by inquiring into the economy of nature, to be thus met at every 
step, with new proofs of the goodness and wisdom of the Author 
of Nature, particularly as manifested towards the human race. 
To discover the character of the Deity, should indeed, be the 
end and aim of all knowledge ; and even should an occasional 
digression from the subject of your present study, retard your 
progress in botanical investigations, the loss tvould be slight, 
compared to the gain of one pious and devout aspiration of the 
heart. 
When we become so deeply engaged in philosophical specula- 
tions, as to forget Him whose works we study, we have wander- 
ed far from the path of true knowledge. It was not thus that 
Newton studied the laws of matter, or Lock and Watts the laws 
of mind, or Paley the animal and vegetable physiology; these 
great and good men, made their rich treasures of knowledge 
subservient to one great design, that of illustrating the charac- 
ter of God, and teaching us our duty to Him. 
LECTURE IX. 
Of leaves. 
You all know what is meant by the leaf of a vegetable ; but 
■were you called on to give a definition to the term leaf, you 
might find it more difficult than at first you would imagine. 
Young persons are often disconcerted, when asked by their 
teachers to explain some word of which they have an idea, and 
yet find themselves unable to give a definition ; but although the 
pupil may be surprised at this fact, it is not unaccountable to 
those who know, that although we may have the picture of an 
object in the mind, it is not always easy to convey our concep- 
tions to the minds of others. To give correct definitions of 
terms, is one of the greatest difficulties in science. The manner 
in which different persons describe objects, varies with the de- 
gree of knowledge possessed respecting their properties. For 
example ; in attempting to describe common salt, if a person 
knew nothing more of it than his unassisted senses had inform- 
ed him, he would speak of its colour, taste, and other obvious 
The goodness of God particularly manifested towards the human race 
— Philosophical speculations sliouid not lead us to forget the Author of na- 
ture. 
Difficulty of giving a definition of a leaf — To give correct definitions one 
of the greatest difficulties in science. 
