Jonis, the son of a Sheffield manufacturer, was born in 1718. After an elementary training, he was placed under the tuition of Dr Doddridge. Passing from this academy, he entered the university of Edinburgh, where he distinguished himself by his logical and metaphysical acuteness, and by great ingenuity in his arguments. Here he formed an acquaintance with Dr Robertson, Mr Hume, and other literary characters. Having completed his medical course at Edinburgh, he afterwards spent some time at the university of Leyden, where in 1743 he took the degree of M.D. Returning to England he commenced practice as a physician at Birmingham. Having substituted leaden vessels in the room of glass ones in the manufacture of sulphuric acid, he was enabled to sell it at a much cheaper rate than had been He accordingly established a manufactory of this material at Prestonpans in the year 1749, which was opposed by Dr Ward, but without success, as Roebuck's discovery did not come within Ward's patent. Dr Roebuck and his partner retained the advantages of their industry and ingenuity for a number of years, supplying the public with sulphuric acid at a much cheaper rate than had been formerly done. He found it expedient to relinquish his medical profession, and he resided in Scotland during the greater part of the year. He made some discoveries in the smelting of ironstone, greatly facilitating that process by using pit-coal instead of charcoal. He and his partner therefore projected a very extensive manufactory of iron, for which they soon procured a sufficient capital, as their friends had much confidence in their integrity and abilities. Dr Roebuck at length made choice of a spot on the banks of the River Carron as the most advantageous situation for the establishment of their manufactory, abundance of ironstone, limestone, and coal being found in its immediate vicinity. The preparations for this establishment were finished in the end of the year 1759; the first furnace was blown on the 1st of January 1760; and a second was soon afterwards erected. These works turned the attention of Dr Roebuck to the state of coal in the neighbourhood, and to the means of procuring the extraordinary supplies which the iron-works might require. He therefore became lessee of the extensive coal and salt works at Borrowstounness, the property of the Duke of Hamilton, in which he sunk, in the course of a few years, not only his own and a considerable part of his wife's fortune, but the regular profits of his more successful works; and, what distressed him above everything else, the great sums of money which he borrowed from his relations and friends, without the prospect of ever being able to repay them. This ruinous adventure cut off for ever the flattering prospects of an independent fortune which his family had once cherished; and he drew from his colliery only a moderate annual support, for which he was indebted to the indulgence of his creditors. It was while engaged in this speculation that he became acquainted with James Watt, the inventor of the modern steam-engine. Some years before his death, he was seized with a disorder that required a dangerous operation, which he bore, however, with his usual spirit and resolution. He visited his works till within a few weeks of his decease, which took place on the 17th July 1794. A pretty copious memoir of Roebuck appeared in the fourth volume of the Transactions of the Royal Society of Edinburgh, of which he was a fellow, in which it is stated that, besides contributing a few papers to that society, as well as to the Royal Society of London, he was likewise the author of two political pamphlets.

The present John Arthur Roebuck, M.P., is the grandson of Dr Roebuck.