'■i^'2 PHILOSOPHICAL TRANSACTIONS. [aNNO 1758. 



the base. In length it measured \ ^ of an inch. It floated on water, and 

 weighed about 126 grs. In the other case a number of small biliary calculi were 



that faculty in June 1750, publighing an inaugural dissertation " De Aeris Factitii Imperio, in Primis 

 Corporis Humani Viis." 



His family thinking him too young, being then but in his 20th year, to settle as a practical physician 

 immediately after taking his degree, he went to Paris, and there perfected himself in anatomy and 

 chemistry under Ferrein and Rouelle. 



In 1751 Dr. Johnstone seated himself at Kidderminster ; and here he was assisted by the good 

 offices of Dr. M'Kenzie, who had retired from practice at Worcester, and by the advice of his former 

 masters Dr. St. Clair and Dr. Whytt. With both these eminent physicians he kept up a regular cor- 

 respondence, and from both he received the warmest tokens of friendship. At Kidderminster he 

 soon became popular ; even the first year of his practice, at the age of 21, he got near ^100, and 

 never afterwards had any occasion to apply to his father for money. It was here that he met with 

 the case of gall-stones, inserted in the present vol. of these Trans. 



From its low situation, and from the jxjpulation being too much crowded in small habitations, 

 malignant fevers and sore throats were often prevalent at Kidderminster, and had proved remarkably 

 fatal} and Dr. Johnstone owed much of his reputation to his success in curing them. He gave mi- 

 neral acids, Peruvian bark, and dulcified acids. He forbad bleeding. He discovered the power of 

 mineral acids in a gaseous state to destroy putrid miasmata, and on his observations and experience 

 he founded the method of cure of putrid fevers, which he published in 1 7 58 in a book entitled " An 

 historical. Dissertation concerning the malignant Epidemical Fever of 1756", &c." London, printed 

 1758. On the discovery of the power of mineral acids in a state of gas to destroy contagions. Dr. 

 John Johnstone has written a pamphlet* asserting and proving his father's prior claim to the disco- 

 very. This pamphlet was answered by Dr. Smyth, in his letter to Mr. Wilberforce The reply 

 of Dr John Johnstone to Dr. James Carmichael Smyth, has very fairly stated and settled the point 

 in dispute. For if the question is to be settled by dates, it is proved that Dr. James Johnstone, sen. 

 promulgated his use of muriatic acid gas in 1758. That Guyton Mon-eau recommended and used 

 muriatic acid gas for purifying the cathedral at Dijon in 1773. That Dr. James Johnstone, jun, in 

 his Treatise on Malignant Angina, published at Worcester in 1779> recommended muriatic acid 

 gas as the surest method to prevent the spread of contagion, and that Dr, James Carmichael Smyth 

 professes not to have discovered the virtues of nitric acid gas till 1780, and did not publish what he 

 professes to have discovered till 1795. 



At Kidderminster, in a very early part of his practice, began Dr. Johnstone's acquaintance with 

 the first lord Lyttelton, with whom he continued on terms of uninterrupted friendship until the 

 death of that learned and pious nobleman. The account he has given of his last illness, under the 

 denomination of "Case of George Lord Lyttelton" is an example of the vigour and purity of his 

 style, and does equal honour to his head and to his heart. 



In the 54th vol. of the Philosophical Transactions Dr. Johnstone published the first sketch of 

 his opinions on the ganglions of the nerves, a subject which he afterwards pursued in the 57th 

 and 60th vols. 'Ihe publication of these papers procured their author the notice and friendship 

 of the illustrious Haller ; with whom Dr. Johnstone's correspondence began in 176" I, and continued 

 till 1775. It consists chiefly of physiological and critical observations on the doctrine of ganglions, 

 to which he very candidly offers objections and admits of reply. In one letter, dated 2,} May J76"9, 

 he says, after some prefatory observations on Dr. Johnstone's doctrine — " For any thing 1 know, 

 there is but one objection (the ophtlialmic ganglion), which lies entirely between nerves dedicated to 



* Account of the Discoveiy of the Power of Mineral Acids in a Sute of Gas to destroy Contagion. London, 1803. 



