TRANSACTIONS OF SECTION B. 649 



light at no very distant period. According to this census we have now realised 

 about 180 such syntheses. The products of Bacteria have been included in the 

 list because these compounds are the results of vital activity in the same sense that 

 alcohol is a product of the vital activity of the yeast plant. On the other hand 

 the various iiro-cooipounds resulting from the transformation in the animal 

 economy of detiiiite chemical substances administered for experimental purposes 

 have been excluded, because I am confining my attention to natural products. Of 

 course the importance of tracing the action of the living organism on compounds 

 of known constitution from the physiological point of view cannot be overesti- 

 mated. Such experiments will, without doubt, in time shed much li^ht on the 

 working of the vital laboratory. 



TJie history of chemical synthesis has been so thoroughly dealt with from time 

 to time that I should not have ventured to obtrude any further notice of this sub- 

 ject upon your patience were it not for a certain point which appeared to me of 

 siitHcient interest to merit reconsideration. It is generally stated that the forma- 

 tion of urea from ammonium cyanate by Wohler in 18i^8 was the tirst synthesis of 

 an organic compound. There can be no doubt that this discovery, which attracted 

 much attention at the time, gave a serious blow to the current conceptions of 

 organic chemistry, because urea was so obviously a product of the living animal. 

 It will be found, however, that about the same "time Henry Hennell, of Apothe- 

 caries' Hall, had really effected the synthesis of alcohol— that is to sav, had 

 synthesised this compound in the same' sense that Wobler had synthesised urea. 

 The history is soon told. In 1826 Hennell (through Brande) communicated a 

 paper to the Royal Society which appears in the ' Philosophical Transactions ' for 

 that year.' In studying the compounds produced by the action of sulphuric 

 acid on alcohol, and known as ' oil of wine,' he obtained sulphovinic acid, 

 which had long been known, and gave fairly good analyses of this acid and of 

 someof its salts, while expressing in the same paper very clear notions as to its 

 chemical nature. Having satisfied himself that sulphovinic acid is a product of 

 the action in question, he then proceeded to examine some sulphuric acid which 

 had absorbed eighty times its volume of olefiant gas, and which had been placed 

 at his disposal for this purpose by Michael Faraday. From this he also isolated 

 sulphovinic acid. In another paper, communicated to the Koyal Society in 1828,- 

 he proves quantitatively that when sulphovinic acid is distilled with sulphuric acid 

 and water the whole of the alcohol and sulphuric acid which united to form the 

 sulphovinic acid are recovered. In the same paper he sliows that he had very 

 clear views as to the process of etherification. Hennell's work appears to have 

 been somewhat dimmed by the brilliancy of his contemporaries who were labour- 

 ing in the same field : but it is not too much to claim for him, after the lapse of 

 nearly seventy years, the position of one of the pioneers of chemical sj'n thesis. Of 

 course in his time the synthesis was not complete, because he did not start from 

 inorganic materials. The olefiant gas used by Faraday had been obtained from 

 eoal-gas or oil-gas. Moreover, in 1826-1828 alcohol was not generally regarded 

 as a product of vital activity, and this is, no doubt, the reason why the discovery 

 failed to produce the same excitement as the formation of urea. But the synthesis 

 of alcohol from ethylene had, nevertheless, been accomplished, and this hydrocarbon 

 occupied at that time precisely the same position as ammonium cyanate. The 

 latter salt had not then been synthesised from inorganic materials, and the forma- 

 tion of urea, as Schorlemmer points out,' was also not a complete synthesis. The 

 reputation of Wohler, the illustrious friend and colleague of the raore illustrious 

 Liebig, will lose not a fraction of its brilliancy by the raising of this historical 

 question. Science recognises no distinction of nationality, and the future historian 

 of synthetical chemistry will not begrudge the small niche in the temple of Fame 

 to which Hennell is entitled. 



' ' On the Mutual Action of Sulphuric Acid and Alcohol, with Observations on the 

 Composition and Properties of the resulting Compound,' Phil. Trans., 1826, p. 240. 



^ ' On the Mutual Action of Sulphuric Acid and Alcohol, and on the Nature of the 

 Process by which Ether is formed,' Phil. Trans., 1828, p. 365. 



' The Rise and I)evelojme7it of Organic Chemistry, p. 195. - '. 



