512 Mr. Connell on the Nature of Lampic Acid. 



Admitting that the azotic element is engaged in the combi- 

 nation as amidogene, and not as ammonia, the above formula 

 converts itself into 



(2 Hg + (2 NH 2 + Hg) + 6 H) 



a method of arrangement which we have already met with as 

 an element of the yellow powder, formed by water on white 

 precipitate. 



LXXII. On the Nature of Lampic Acid, By Arthur 

 Connell, Esq., F.R.S.E* 



I T is well known that Professor Daniell, to whom we are 

 -* indebted for a knowledge of the properties of this acid 

 liquid, ultimately came to the conclusion that it is acetic acid 

 containing some disoxygenating substance which bestows its 

 property of reducing metallic oxides. 



A few years ago I had occasion to examine this acid, as 

 <well as that resulting from the action of potash on alcohol, 

 and that obtained by distilling a mixture of alcohol, peroxide 

 of manganese, and sulphuric acid, and I came to the conclu- 

 sion that they all contained formic acid besides acetic acid. 

 The grounds on which the existence of formic acid in them 

 was inferred, were that they all reduced the oxides and salts 

 of mercury and silver with effervescence, and that they all were 

 capable of yielding perfectly well characterised formates of 

 lead and of magnesiaf. 



About the same time M. Leopold Gmelin came by indepen- 

 dent observation to the same conclusion as myself respecting 

 the acid from alcohol, oxide of manganese and sulphuric acid| ; 

 and as the manner in which I had examined the three liquids, 

 the results which I had obtained, and the conclusions which 

 I had drawn regarding them, were the same in all the three 

 cases, I could not avoid regarding M. Gmelin's experiments 

 as amounting to a verification of the view which I had given 

 regarding all the three acid liquids. 



In a late memoir, however, on the products of the oxida- 

 tion of alcohol §, M. Liebig once more asserted the peculiar 

 nature of lampic acid by maintaining that it was " probable, 

 not to say certain," that lampic acid is identical with a pecu- 

 liar acid, which this distinguished chemist supposes is formed 

 by the action of oxide of silver on aldehyde, and to which he 

 has given the name of the aldehydic. M. Mitscherlich, in the 



* Communicated by the Author. 



t Edinb. New Phil. Journal, vol. xiv. p. 231. 



j Poggend. Anna!., xxviii. 508. 



§ Annates de Chim. et de Physique, lix. 289. 



