Annual Report of the Council. 293 



no closer connection with benzoic acid than with train oil or 

 coal from which it also might be obtained. How Liebig 

 became acquainted with the fact that benzene is formed 

 by the dry distillation of coal is not known, as his pupil 

 Hofmann, who obtained it in 1845 from coal-tar observes : 

 " It is frequently stated in memoirs and text-books that 

 coal-tar oil contains benzol. I am, however, unacquainted 

 with any research in which this question has been 

 investigated." 



The writer, taking an interest in this question, asked 

 Mr. Dale if he could give him any information, and thus 

 elicited the following interesting facts. About 1834, at the 

 time when Mitscherlich had converted benzol into nitro- 

 benzol, the distillation of coal-tar was carried out on a large 

 scale in the neighbourhood of Manchester ; the naphtha 

 which was obtained being employed for the purpose of 

 dissolving the residual pitch and thus obtaining a black 

 varnish. Attempts were made to supplant wood-naphtha, 

 which at that time was used in the hat factories at Gorton 

 for the preparation of " lacquer " by coal-tar naphtha. The 

 substitute however did not answer, as the impure naphtha 

 gave off on evaporation so unbearable a smell, that the 

 workmen refused to employ it. It was also known about 1838 

 that wood-naphtha contained oxygen, while that from coal- 

 tar did not, and hence Mr. Dale attempted to convert the 

 latter into the former, or into a similar body. By acting 

 on it with sulphuric acid and nitre, he obtained a liquid 

 possessing the smell of bitter almonds, which, however, he 

 did not examine any further. This was done by Mr. John 

 Leigh, who, at the meeting of the British Association held 

 in Manchester, 1842, exhibited a considerable quantity of 

 nitrobenzol and dinitrobenzol before the Chemical Section, 

 Dalton being the president. Thus, for the first time, it was 

 proved that coal-tar contains a considerable quantity of 

 benzol. Liebig was in England at this time, and, if the 



