order to become acquainted with the diseases of the torrid zone. The physician who studies new and local forms of disease, with their symptoms, and natural and accidental terminations, whatever may be his success as a medical practitioner, may justly be said to perform good service to his kind. His observations are not of less value than those of the cautious and expert navigator, who searches and describes shores hitherto unknown. But, while thus seeking to avert disease from others, Dr Bisset became himself liable to its ravages. Having, in 1745, contracted ill health at Greenwich in Jamaica, he was under the necessity of resigning his situation as second surgeon, in order to return to Britain. In May, 1746, he purchased an ensigncy in the 42nd (Highland) regiment, so well known for a long train of military glories, and which was then commanded by Lord John Murray. By this transition, his attention was turned from the medical to the military profession, and fortification became his favourite study. After a fruitless descent on the coast of Brittany in September, 1748, and passing a winter at Limerick in Ireland, the regiment was, in the beginning of next campaign, brought into action at Sandberg, near Hulst, in Dutch Flanders, where one Dutch and two English regiments suffered very severely. Here Dr Bisset employed himself in drawing a sketch of the enemy's approaches, and some time after, in another of Bergen-op-Zoom, with the permanent lines, the environs, and the enemy's first parallel; which were presented by his colonel to the Duke of Cumberland, the commander-in-chief. The Duke was so much pleased with these specimens of Dr Bisset's military knowledge, that he ordered him to attend the siege of Bergen-op-Zoom, and give due attention daily to the progress of both the attack and the defence, in order to form a journal of the whole proceedings. This distinguished duty Dr Bisset undertook with a modest reluctance, the result rather of inexperience than of any consciousness of want of knowledge. The result, however, was highly honourable to him. His journals, duly illustrated with plans, were daily delivered to Lord John Murray, who forwarded them every second or third day, to the Duke, who was then at Maestricht, at the head of the allied army, observing the motions of the French army under Marshal Saxe. His royal highness was pleased to express his approbation, by recommending Dr Bisset to the Duke of Montagu, then master-general of the ordnance, who honoured him with a warrant as engineer extraordinary to the brigade of engineers; he was at the same time promoted to a lieutenancy in the army.
At the end of the war, being placed on half-pay, he had full leisure to pursue his studies in fortification, and also to visit the principal specimens of the art upon the Continent. The result was his "Essay on the Theory and Construction of Fortifications," which appeared in 1751, in 8vo.
His attention being now disengaged from this pursuit, he resumed his original profession, and, for the sake of a salubrious air, which was necessary to his weakly constitution, retired to practise at the village of Skelton, in Cleveland, Yorkshire, where he spent all the remainder of his life. In 1755, when the Seven Years' War was impending, he published a "Treatise on the Scurvy, with Remarks on the Cure of Scorbutic Ulcers," which he dedicated to Viscount Anson, and the other Lords of the Admiralty. In 1762, appeared his "Essay on the Medical Constitution of Great Britain," which he inscribed to his friend Sir John Pringle. In this work he shows the effects of the change of weather, and of the seasons, on the diseases of Great Britain; and at the conclusion is an interesting paper on the virtues of the herb Bear's-foot, in the cure of worms. In 1765, the University of St Andrews conferred upon him the degree of M.D. In 1766, he published, at Newcastle, a volume of "Medical Essays and Observations," in which are upwards of twenty papers on the climate and diseases of the
