Nature of the Lampic Acid, 237 



forms with barytes and lime. The former afforded prismatic 

 crystals, and the latter an imperfect crystalHzation, resembHng 

 that of formate of Time. A concentrated solution of nitrate of 

 silver is also reduced by it, like nitrate of mercury ; effects 

 which may be imitated with mixtures of acetic and formic acids. 



2. Nature of the Lampic Acid, — I have already mentioned, 

 that it occurred to me at an early period of the investigation, 

 that the acid from alcohol and potash might prove to be of an 

 analogous nature with the lampic ; and as soon as I had deter- 

 mined the nature of the former of these products, I thought it 

 extremely probable that the latter also would be found to con- 

 sist of a mixture of acetic and formic acids. 



The lampic acid, which was discovered by Sir Humphry 

 Davy, was first examined by Mr Faraday, and was considered 

 by him as a peculiar body * ; although, from the very small 

 quantities he was enabled to operate upon, he did not obtain 

 any very definite result. It was afterwards more fully examined 

 by Mr Daniell, who came to the conclusion, that it was a new 

 acid body, and gave it the name which it still bears "f*. Subse- 

 quent experiments, however, induced Mr Daniell to alter his 

 opinion as to its nature, and to conclude, that it was acetic acid, 

 but combined with some substance of a highly disoxygenating 

 nature, to which it owed its property of reducing metallic salts. 

 He was, however, unable to separate this substance from the 

 lampic acid procured from sulphuric ether, or to determine its 

 nature ; but he supposed that it was some compound of carbon 

 and hydrogen, differing from ether or alcohol \. Very lately, 

 it would appear, that Dobereiner has once more revived the 

 idea, that the lampic acid is a substance of a peculiar nature, 

 and differing both from acetic and formic acids §. I shall pro- 

 ceed, however, now to state the grounds on which I conceive 

 it follows that the lampic acid from sulphuric ether really 

 consists of* a mixture of acetic and formic acids ; and that the 

 formic acid is the substance which bestows upon it its peculiar 

 reducing qualities. The arrangement adopted for the prepara- 

 tion of the acid, was the following. A small evaporating basin 



• Journal of Royal Institution, iii. 77. f Ibid. vL 318. 



$ Ibid. xii. 64. § Poggend. Annal. xxiv. 608. 



