out reference to the historical order, a few of the achievements of chemists, which have from time to time astonished and delighted the world, may here be briefly noted. Among vegetable products are oxalic acid, which was formed directly from carbonic acid, a combination of two carbon-atoms being necessary in the process; valeric acid, containing five carbon-atoms; malic acid, with four carbon-atoms, one of the most widely-distributed acids of the vegetable kingdom, being contained in a large number of unripe fruits; cinnamic acid, containing nine atoms of carbon; tartaric acid, the acid of grape-juice. Wintergreen oil, obtained from Gaultheria procumbens, has been found to consist mainly of an organic ether, which can be, and has been, prepared artificially. The oil of garlic (Allium sativum) contains carbon, hydrogen, and sulphur. It can be prepared with all its properties without the plant. The oil of mustard, with its peculiar arrangement of carbon, hydrogen, nitrogen, and sulphur, is now manufactured on the large scale by a patented process, the mustard-plant being outrivaled by the chemist. The deadly poison conine, and the beautiful colors alizarine and indigo, finally, belong in the same list. In regard to alizarine or Turkey-red, it may be remarked that the discovery of the methods for its artificial preparation has led to the establishment of an important branch of industry of far-reaching influence. It is doubtful, however, whether as much will ever be said concerning the preparation of indigo. Among animal products that have yielded up the secrets of their internal structure to the chemist are the simple fats and the lactic acids. In a great many portions of the animal organism, as the brain, pancreas, liver, lungs, the thyroid and thymoid glands, is found a substance, containing six atoms of carbon, which has been called leucine. This substance is also a frequent product of the decomposition of organic bodies. Leucine is obtained more readily by artificial means than it can be extracted from the tissues in which it exists ready formed. A constant ingredient of the juice of flesh is creatine; and one of the products of decomposition of creatine is sarcosine. Both creatine and sarcosine can be constructed from the elements by purely chemical processes. Taurine, which occurs in the bile, in the contents of the alimentary canal, in the lung-tissue and the kidneys, and contains carbon, hydrogen, nitrogen, oxygen, and sulphur, can be prepared by a very simple process.
These examples suffice to indicate the character of the results already achieved, and furnish justification for the hope now entertained by chemists that in good time it will be possible to produce all chemical substances in the laboratory. No one who has given the subject a sufficient amount of attention to enable him to form an opinion can for a moment feel a doubt on this subject.
The old dogma no longer exists. There are those who sigh at its death; who consider that the sacrilegious step of Science which annihilated it has, in some way, tended to lessen the mystery of life, and
