216 Royal Society : Anniversary Proceedings^ 1843. 



Before he returned to Scotland he visited Brussels, and was much 

 noticed by Count Lockhart, the Austrian Viceroy of the Nether- 

 lands. From Brussels he ascended the Rhine in company with 

 an English artist named Green, who was making a professional tour, 

 and who afterwards acquired some celebrity as a landscape painter 

 in water-colours, an art then in its infancy. At Weimar he made 

 the acquaintance of the illustrious Goethe; and, having visited 

 Berlin, he came to Paris shortly before the breaking out of the Re- 

 volution in 1789. 



As Mr. Macintosh's pecuniary circumstances did not admit of his 

 continuing unemployed, at the time of his return to Scotland several 

 schemes for his future career in life appear to have attracted his at- 

 tention. . He was at one period upon the point of embarking as a 

 planter for the West Indies, and had actually entered upon ne- 

 gotiations with the Hudson's Bay Company to retrace the steps of 

 the adventurous Hearne to the shores of the polar ocean, with the 

 view of extending the Company's fur trade beyond the Rocky 

 Mountains. His love for chemistry induced him, however, to relin- 

 quish these schemes, and, as the result, his establishment of various 

 branches of chemical manufacture, including those of acetate of lead, 

 hitherto in Britain altogether an import from Holland ; of acetate of 

 alumina, so extensively employed by our calico-printers ; of alum, 

 before his time unknown as a manufacture in Scotland, and whereby 

 he converted the exhausted and deserted coal-works in the neigh- 

 bourhood of Campsie and Hurlet, near Glasgow, into a scene of 

 great and active commercial enterprise ; of Prussian blue, and of 

 prussiate of potash, as the mode of dyeing woollen, cotton and silk 

 (with which latter salt he was also the sole inventor), followed each 

 other in rapid succession. He was also the inventor of the process 

 for manufacturing the dry chloride of lime, which effected an entire 

 revolution in the process of bleaching, and which gave origin to the 

 stupendous chemical works at St. Rollox, near Glasgow, which have 

 since become so celebrated under the energetic management of the 

 Messrs. Tennants. 



It had been known to chemists that naphtha, or petroleum, was 

 a solvent for caoutchouc, or the coagulated juice of the Iatropa 

 Elaslica, the Urceola Elastica, and other tropical plants. The 

 liquid varnish, however, thus formed, although elastic, continued 

 clammy and viscid when exposed to the air of the atmosphere. Mr. 

 Macintosh overcame this difficulty by the formation of double fabrics, 

 having the varnish as an adhesive waterproof film or medium in the 

 centre. It is unnecessary to enlarge upon the great utility of this 

 invention, followed as it has been by the removal of many of the 

 difficulties which had rendered caoutchouc a substance imprac- 

 ticable to manage, so as now to admit of its application to many 

 useful purposes in the arts. Mr. Macintosh was also the inventor 

 of a mode of converting iron into steel by the application of coal-gas 

 in hermetically closed and heated vessels ; a beautiful process, by 

 which much time and labour is saved. 



The desire of acquiring useful information continued with Mr. 



