^10 NINETEENTH CENTURY. PT. in. 



is no longer working in the dark, as he was when he could 

 merely judge by outward effects. In quite another branch, 

 less important, but still of great interest, the chemistry of 

 organic compounds has been most useful. In 1825 Fa la- 

 day extracted from coal-tar an important substance called 

 benzole, and from this a heavy colourless liquid, 'aniline,' 

 can be obtained. In 1856 Mr. Perkins discovered that by 

 adding hypochlorite of sodium to this liquid a lovely mauve 

 colour was produced, and this has led to the discovery of 

 all the beautiful aniline dyes which are now prepared both 

 from living plants and from the coal-tar which comes from 

 plants of bygone ages. 



It would be impossible to give a list even of the leading 

 chemists of the present day. Wohler, Graebe, Hoffmann, 

 Wiirtz, Frankland, and Williamson, are only a few among 

 equally illustrious names, and it must yet be many years 

 before a fair sketch can be given of the history of the 

 chemistry of the organic compounds ; but we may be sure 

 that such a future historian will, as Dr. Andrews has said, 

 'have to record a succession of beneficent triumphs, in 

 which the effects of science have led to results of the highest 

 value to the wellbeing of man.' 



Chief Works consulted. Davy's 'Works,' 1840; Whewell's 'In- 

 ductive Sciences;' Dalton's 'Chemical Philosophy,' 1808 ; Dr. Henry's 

 'Memoir of Dalton,' 1854; Fownes's 'Chemistry;' Brande's 'Chem- 

 istry;' Faraday's 'Various Forces of Nature;' 'Edinburgh Review,' 

 vol. xciv. 'Modern Chemistry;' Hoffmann, 'On Liebig and Fara- 

 day;' Liebig's Scientific Attainments, 'Contemporary Review,' April 

 1877- 



