487 



but it was in the branch of chemical investigation that he was 

 destined to become more conspicuous. The experiments which he 

 afterwards made in the application of incinerated Algse, as a ma- 

 nure, and which are related by Dr. Greville in his account of the 

 British Algae, come more under the head of chemical than of 

 botanical research. In order to perfect him in a knowledge of the 

 French language, the subject of this notice was afterwards removed 

 to the house of a Catholic clergyman in Champagne, with whom he 

 resided for some time, and acquired a facility in speaking and 

 writing French, which he retained through life. 



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- 

 gociations 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 \yorks 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, Avas 

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

 Elastica, 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 a-s an adhesive waterproof film or medium in the 



