“Your chemists have just arrived at that point of knowledge where ours were forty centuries ago. Yours recognize over sixty forms of matter as simple and elementary, while ours have reduced them all to one,--the unit out of which all creation is formed. From this you may infer that our discovery of the compound nature of the metals enables us to make them at pleasure. This was a most fortunate and timely knowledge for us, since they are distributed very sparsely on our planet. It will no doubt be a strange thing to tell you, that we make gold at a less cost than iron, and that consequently it is the cheapest metal in use. You are about to ask me whether we make diamonds. We have made them for centuries. Our factories turn them out in masses for the ornamental parts of buildings, for which they are remarkably adapted on account of their brilliancy and indestructibility.” My strange visitor rested a little here, with the evident intention of reading my thoughts, and of enjoying my surprise. While I was marvelling what great things chemical science must have done in other ways, he appeared to anticipate my question. “My brother,” said he, “we are indebted to the science of chemistry for more than I can readily enumerate. With us, as with you, a large number of common and abundant substances differ only a trifle in chemical composition from others which are in great demand for the purposes of life. The science of chemistry enables us to convert one into the other at will. Thus, from wood we manufacture sugar, starch, and any number of other useful commodities. By the double decomposition of air and water we generate a heat which, for economy and easy regulation, is better than anything the universe affords. The clumsy, unclean and inconvenient use of wood and coal for fuel is with us a practice of the past. “But chemistry has done for us an immeasurably greater service. It has enabled us to provide for ourselves a food supply by the process of synthesis, which, in the extremity of crop shortage or failure, we can resort to as a means of averting famine. You are aware, in your present stage of chemical knowledge, that all food products are composed of four simple ingredients, Carbon, Oxygen, Hydrogen and Nitrogen, found in abundant supply in the atmosphere and its natural mixture. These, with two or three earthy matters from the soil, are the constituents of all food. We forestall the slow assimilation of these by the organs of animals and plants, and by our chemical skill are enabled to combine them in proper proportion to form the proximate elements of all varieties of food, wanting in nothing but the taste and flavor of the natural supply, and on that account, only used when compelled by necessity.