1907.] on FrobUms of Applied Cliemistry. 561 



not accomplished up to date), he discovered the colouring matter 

 called " mauve," the forerunner of all colours produced from coal-tar : 

 and only a year later, at an age when, on the Continent, the great 

 majority of young men are either still at school, or at least entirely 

 innocent of any taste for practical life, and when they only enter 

 upon their theoretical studies, he built a factory for producing his 

 mauve, which at once proved a success and laid the foundation for 

 his splendid work in after life. This is not the place to enlarge upon 

 liis later career, which is almost unique in combining inventive genius 

 with the true spirit of pure science. 



We need not be surprised to find that sometimes even the most 

 •eminent practical men threw away much time and capital on inven- 

 tions which, in the end, turned out failures. Sometimes this was due 

 to the fact that, owing to their ignorance of the scientific principles 

 of the case, they hit upon a wrong idea and pertinaciously clung to 

 it, unmoved by constant mishaps which they hoped to overcome by 

 patience and perseverance. But not unfrequently failures occurred, 

 even where the original idea was a good one, which, in the end, was 

 carried to a successful issue. The cause of this may be that the 

 inventor had overlooked some difficulty, apparently unessential, but 

 in effect fatal to success. Or else the proper mechanical means for 

 carrying out the idea were not discovered by the inventor nor the 

 experts consulted by him. I beg leave to illustrate this by a remark- 

 able instance. One of the great problems presented to applied 

 chemistry in the last century, at which many inventors in all 

 industrial countries have been working, was the utilisation of " alkali- 

 waste," that is the residue resulting from the extraction of crude soda 

 by the Leblanc alkali process, which occupies a large space, and 

 which for generations caused an unbearable nuisance for miles around 

 the works by contaminating air and water. The first partial success 

 in this direction was scored in 1861 by Ludwig Mond at Cassel — 

 later on at Widnes, and by Max Schaffner at Aussig. But the 

 endeavours to solve that problem are much older. One of the first 

 patents referring to it was taken out in 1837 by G-ossage, one of those 

 great captains of English chemical industry whose name I have 

 already cited. Already, at that date, he had conceived the idea of 

 decomposing and utilising the calcium sulphide, which is the princi- 

 pal constituent of alkali-waste, and which, at the same time, is the 

 cause of the nuisance produced by that waste. The idea was to treat 

 the waste with moist carbonic acid, which interacts with the calcium 

 sulphide to form calcium carbonate and hydrogen sulphide. Gossage 

 quite rightly recognised a number of the conditions necessary for 

 realising that reaction, but unfortunately not all of them. To 

 mention only one thing in which he failed : neither Gossage himself, 

 nor anybody else for many years afterwards, hit upon a practicable 

 method of dealing with the dilute hydrogen sulphide formed. After 

 working incessantly at this problem for seventeen years, Gossage 

 Vol. XYIII. (No. 101) 2 o 



