Annual Report of the Council. 295 



Dale's greatest achievement was, however, the manufac- 

 ture of oxalic acid from saw-dust. Up to this period it was 

 obtained by oxydising sugar or starch with nitric acid. 

 Gay-Lussac had already shown in 1829, that this acid is also 

 produced by heating vegetable fibre, sugar, starch, gum, and 

 tartaric acid with caustic potash. Neither scientific chemists 

 nor practical men attended to this subject until Mr. Dale 

 took it in hand. In his attempt to do so, he was met with 

 -a number of serious obstacles, chiefly of a practical nature. 

 These, however, he, by dint of uncommon ingenuity, 

 and by the application of an amount of perseverance of 

 which, perhaps, but few men are capable, succeeded in 

 overcoming, and the process was then soon in full and 

 successful operation at Messrs. Roberts, Dale, and Co.'s 

 works, at Warrington. None of the scientific chemists 

 who attended the Manchester Meeting of the British 

 Association in 1861, when Kekul6 was his guest, will 

 forget the day when Mr. John Dale conducted them 

 over the works and explained the process to them in his 

 peculiarly lucid manner. The only practical suggestion which 

 •Gay-Lussac had made consisted in the proposal to convert 

 cream of tartar by his method into oxalic acid. At that 

 time tartaric acid was cheaper than oxalic acid, and the 

 suggestion might, therefore, under the circumstances of the 

 time, have proved of some practical value. It was evident, 

 however, that for the purpose of ensuring success a cheaper 

 material had to be chosen. Dale found woody fibre in the 

 shape of saw-dust to answer perfectly. Gay-Lussac had 

 stated that potash might be replaced by soda ; Mr. Dale, 

 however, found that saw-dust yields hardly any oxalic acid 

 when fused in the soda. On the other hand, potash was 

 found to be too expensive, and the process would not pay. 

 He overcame the difficulty by using a mixture of two 

 equivalents of soda to one of potash, which answers 

 not only as well as potash alcne, but has the great 



