Mr. Schoolcraft's first work was an elaborate treatise, but partially known to the public, entitled Vitreology, which was published in 1817. The design of it was to exhibit the application of chemistry to the arts in the fusion of siliceous and alkaline substances in the production of enamels, glass, etc. He had had opportunities of experimenting largely and freely by his position as conductor for a series of years of the extensive works of the Ontario Company at Geneva in New-York, the Vermont Company at Middlebury and Salisbury in Vermont, and the foundry of crystal glass at Keene in New Hampshire. In 1818, and the following year, he made a geological survey of Missouri and Arkansas to the spurs of the Rocky Mountains, and in the fall of 1819 published in New-York his View of the Lead Mines of Missouri, which is said by Professor Silliman to have been "the only elaborate and detailed account of a mining district in the United States" which had then appeared. It attracted much attention, and procured for the author the friendship of many eminent men. In the same year he printed Transallegania, a poetical _jeu d'esprit_ of which mineralogy is the subject, and which preceded some clever English attempts in the same vein. It was republished in London by Sir Richard Phillips in the next year. Early in 1820 he published a Journal of a Tour in the Interior of Missouri and Arkansas, extending from Potosi toward the Rocky Mountains. His writings having attracted the notice of the government, he was commissioned by Mr. Calhoun, then Secretary of War, to visit the copper region of Lake Superior, and to accompany General Cass in his expedition to the head waters of the Mississippi. His Narrative Journal of this tour was published in 1821, and was eminently successful, an edition of twelve hundred copies being sold in a few weeks. In the same year he was appointed secretary to the commission for treating with the Indian tribes at Chicago, and on the conclusion of his labors published his sixth work, entitled Travels in the Central Portions of the Mississippi Valley, in which he described the country between the regions of which he had given an account in his previous works. His reputation was now widely and firmly established as an explorer, and as a man of science and letters. From this time his attention was devoted principally to the Red Race, though he still cultivated natural history, and wrote occasionally for the reviews and magazines.