Page:An introduction to physiological and systematical botany (1st edition).djvu/42

 12 with this delightful science. Botany has one advantage over many other useful and necessary studies, that even its first beginnings are pleasing and profitable, though pursued to ever so small an extent; the objects with which it is conversant are in themselves charming, and they become doubly so to those who contemplate them with the additional sense, as it were, which science gives; the pursuit of these objects is an exercise no less healthful to the body, than the observation of their laws and characters is to the mind.

In studying the functions of the Vegetable frame, we must constantly remember that it is not merely a collection of tubes or vessels holding different fluids, but that it is endowed with life, and consequently able not only to imbibe particular fluids, but to alter their nature according to certain laws, that is, to form peculiar secretions. This is the exclusive property of a living being. Animals secrete milk and fat from food which has no resemblance to those substances; so Vegetables secrete gum, sugar, and various resinous substances from the uniform juices of the earth,