152 Mkthod of ohlain'mg Formic Acid. 



and liis ship, committed the account of his voyage to America 

 to the deep, in the distant hope of reaching some habitable 

 shore, it is conjectured here among the learned, that tlie \vax 

 cloth discovered by the friar is the siine that Columbus is said 

 to have put into a cask and given ta the deep, when he and his 

 crew were momentarily expecting to perish." 



It appears from some recent experiments of M. Gehlen, that 

 the best method of obtaining formic acid in abundance, is to 

 procure in the first place a formiate of copper. For this purpose, 

 the exjsressed juice of ants is to be supersaturated by carbonate 

 of pota^^h, and sulphate of iron at the maximum is to be poured 

 into the liquor. The yellow liquid being filtered and evaporated 

 to the consistence of syrup, was then distilletl with a sufficient 

 quantity of sulphuric acid. The liquor which had passed into 

 the receiver was very acid, without containing sulphureous acid. 

 It was saturated bv means of carbonate of copper, and the solu- 

 tion furnished bv evaporation fine blue crystals of formiate of 

 copper. This salt was made use of for a comparative examina- 

 tion with the acetate of copper. 



Thirteen ounces of this formiate of cop^per were distilled in a 

 retort with eight ounces 310 grains of sulphuric acid of the 

 specific gravity of 1'864. By the action of the sulphuric acid, 

 there were obtained at a second rectification six ounces 410 

 grains of a distilled product, free from sulphuric acid, which 

 possessed the following properties: 



A sour and pungent odour, reniaining always liquid even at a 

 very low artificial temperature. 



Its specific gravity at a temperature of 16" R. is 11 16*8, 

 whereas that of the concentrated acetic acid is only 1070'9. 



200 grains of cajbonate of soda dej^rived of water require for 

 their saturation \'6o'2 grains of formic acid, diluted in three 

 parts water, and left by evaporation a residue of 228 grains in 

 weight ; whereas a similar quantity of carbonate of soda absorbed 

 1072 grains of acesic acid, and left 2.90 grains of dry residue. 



The formic acid distilled witii its weight of alcohol presents 

 the same phaenomena with those remarked in the preparation 

 of acetic ether, with the exception of a very decided smell of 

 peach kernels. 



Rectified formic ether has a strong but agreeable smell, like 

 that of peach kernels. The taste is the same, with a flavour of 

 ants. The spirit of ants sold in the shops has also this smell, but 

 M. Gehlen did not discover the slightest traces of prussic acid. 



M. Bucholz, the German chemist, has published in Troms- 

 dorff's Journal an analysis of the substance called Benzoin. 



H« 



