Page:Popular Science Monthly Volume 6.djvu/165

Rh will remain but to effect the composition of albuminous substances, in order to give us the complete mastery of the processes which Nature follows in her elaboration of immediate principles. That gift of making its object a reality, which is the peculiar privilege of chemistry, is also one of the strongest arguments to bring in proof of the absoluteness of those laws which we ascertain respecting the system of forces external to us.

Linnæus, whose mind was remarkably analytical and classifying, has not only arranged vegetables and animals in order, but has also classified diseases, and even odors. He refers the latter to seven classes: aromatic odors, such as that of laurel-leaves; fragrant, like those of lilies and jasmine; ambrosial, such as amber, musk, etc.; garlicky, like that of garlic; fetid odors, like those of the goat, the orrage, and others; disgusting odors, as those of many plants of the solaneæ order; and, last of all, nauseous odors. The terms of Linnæus have generally become current in language, but we understand, of course, that their value is merely conventional. As we have said before, there is no standard for the comparison of odors. We can only describe them by making comparisons between them, according to the degrees of resemblance existing between the impressions with which they affect our olfactory membrane. They have no qualities capable of being rigorously defined. This is the reason why it is impossible to give them any natural classification.

The sensations produced by smells are perceived and judged of in a great variety of ways, though with less of difference than prevails as to tastes. "I have seen a man," says Montaigne, "fly from the smell of apples quicker than from a cannonade." The instance he alludes to in this passage is that of Quercet, Francis I.'s secretary, who rose from table and took flight whenever he saw apples upon it. History tells us that Louis XIV. could not bear perfumes. Grétry was greatly annoyed by the odor of roses; that of a hare caused Mdlle. Contat to faint. Odors which disgust us, like that of asafœtida and of the valerian-root, are on the contrary highly enjoyed by the Orientals, who use these substances for condiments. Among-other singular instances related by Cloquet on this subject, we will mention that of a young girl who took the greatest delight in inhaling the scent of old books, and that of a lawyer to whom the exhalations of a dunghill yielded the most agreeable sensations. So that it is out of our power to fix general rules with respect to the influence of odors on our organs, and the character of the sensations which they effect in us; still, from a purely physiological point of view, it is certain that some of them exercise a uniform influence. Chardin and other travelers mention that, when musk-hunters take from the animal the pouch containing musk, they must have the nose and mouth covered by a