Dr. Roebuck's inquiries had an almost exclusively practical direction, and in pursuing them his main object was to render them subservient to the improvement of the industrial arts. Thus he sought to devise more economical methods of producing the various chemicals used in the Birmingham trade, such as ammonia, sublimate, and several of the acids; and his success was such as to induce him to erect a large laboratory for their manufacture, which was conducted with complete success by his friend Mr. Garbett. Among his inventions of this character, was the modern process of manufacturing vitriolic acid in leaden vessels in large quantities, instead of in glass vessels in small quantities as formerly practised. His success led him to consider the project of establishing a manufactory for the purpose of producing oil of vitriol on a large scale; and, having given up his practice as a physician, he resolved, with his partner Mr. Garbett, to establish the proposed works in the neighbourhood of Edinburgh. He removed to Scotland with that object, and began the manufacture of vitriol at Prestonpans in the year 1749. The enterprise proved eminently lucrative, and, encouraged by his success, Roebuck proceeded to strike out new branches of manufacture. He started a pottery for making white and brown ware, which eventually became established, and the manufacture exists in the same neighbourhood to this day. The next enterprise in which he became engaged was one of still greater importance, though it proved eminently unfortunate in its results as concerned himself. While living at Prestonpans, he made the friendship of Mr. William Cadell, of Cockenzie, a gentleman who had for some time been earnestly intent on developing the industry of Scotland, then in a very backward condition. Mr. Cadell had tried, without success, to establish a manufactory of iron; and, though he had heretofore failed, he hoped that with the aid of Dr. Roebuck he might yet succeed. The Doctor listened to his suggestions with interest, and embraced the proposed enterprise with zeal. He immediately proceeded to organize a company, in which he was joined by a number of his friends and relatives. His next step was to select a site for the intended works, and make the necessary arrangements for beginning the manufacture of iron. After carefully examining the country on both sides of the Forth, he at length made choice of a site on the banks of the river Carron, in Stirlingshire, where there was an abundant supply of wafer, and an inexhaustible supply of iron, coal, and limestone in the immediate neighbourhood, and there Dr. Roebuck planted the first ironworks in Scotland.