424 Miscellaneous Intelligence, . 



gave ijfdr certt.v 40 carbon, 48.3 oxyg-en, and 11.7 hydrogeny but no 

 azote. Lyedpodium gave per cent. bO.2 carbon, 39.2 oxysren, and 

 8.6 hydrogen. Aj^ain no azote. — Bibliotheque Universelle.lSSO. 45, 



23. Production of Formic i4cid.^— Dobereiner first obtained this 

 acid artificially, by the distillation of tartaric and sulphuric acids 

 with oxide of manganese. Tunnerman observed that if a mixture 

 of starch, peroxide of manganese, and weak sulphuric acid were 

 heated in a large retort, rapid effervescence, with the evolution of 

 much carbonic acid, occurred at a certain moment, and the mixture 

 acquired the odour of formic acid. By distillation, formic acid came 

 over, accompanied by an odorous substance, acting upon the eyes* 

 but separable by combination of the acid with bases. Tunnermaji 

 mistook the nature of this acid. Wohler established its true cha«* 

 racter. Liebeg, about the same time, obtained it, not only from 

 starch, but by the similar use of many other substances. Gmelin 

 obtained it in the same way from sugar, sugar of milk, starchy 

 lignine, the root of the marsh-mallow, mucous acid, &c. ; but it was 

 always soiled, particularly when obtained from starch, by apecuiiap 

 principle separable by the process of forming salts, and decompo* 

 sing them by sulphuric acid. 



A very pure formic acid may be obtained by distilling alcohol 

 with sulphuric acid and black oxide of manganese ; but to prevent 

 the formation of sulphuric ether, it is convenient to employ dilute 

 alcohol or ordinary spirit of wine : for if the alcohol be strong, there 

 will be produced sulphuric and formic ether, which will not only 

 diminish the quantity of formic acid, but when the latter is combined 

 with oxide of lead, will occasion the formation of a coloured salt, 

 crystallizable with difficulty only. Acetic acid acted upon in the 

 same way gives no formic acid. The fibrine of blood produces a 

 little, but it is very inferior. — Annales de Chimie, xliii. 199. 



24. On a new Acid contained in the Urine of Herbivorous Animals y by 

 M. Liebeg, — ^The following abstract is made from M. Liebeg's paper, 

 published at length in the Annales de Chimie, xHii. 188. Fourcroy 

 and Vauquelin discovered a particular acid in the urine of certaia 

 animals, which they took for benzoic acid, and which appears to be 

 the same as the one to be described. When the urine of the horse 

 is mixed with excess of muriatic acid, a yellow-brown crystalline 

 precipitate is gradually formed, having an unpleasant odour, which 

 cannot be removed by simple washing with water. It is to be 

 boiled with quick lime and water, the liquid filtered, a solution of 

 chloride of lime added, until all urinous odour ceases, and then 

 animal charcoal added, until the liquor which passes the filter iS 

 colourless. This liquid, whilst hot, is to be mixed with great excess 

 of muriatic acid, and left to cool. There separate prismatic 

 crvstals 2 or 3 inches long, of a shining white colour, translucent, 

 and which differ from benzoic acid, not only in the form of its crys- 

 tals, but by its STnaller degree of insolubility in water, by the differT 



