THE WOOD ANT. 117 



tance, and if a nest be broken open, and a bare hand 

 placed within the aperture, it will be speedily covered 

 with a thousand little dots of pungent fluid ; and if the 

 skin be very sensitive it will smart as though it had 

 been plugged into a bunch of stinging nettles. The 

 scent of this fluid is strongly acid, like highly con- 

 centrated vinegar, and even at a distance of a yard from 

 the nest produces an unpleasant sensation in the throat 

 and nostrils. 



One of my friends, desirous of testing personally 

 the peculiar scent, made a breach in the nest of the 

 wood-ant, and put his face to the hole. Scarcely had 

 he approached within three inches than he started 

 back, vowing that the ants had stung him all over his 

 chin, and could not for some time be convinced of his 

 error. 



This pungent liquid is acid in its nature, and when 

 analysed is found to contain two kinds of acid, one pe- 

 culiar to these insects and called ' Formic ' acid, and 

 the other the substance called ' Malic ' acid, which gives 

 to the juice of apples its peculiar flavour. Not only has 

 it the scent of vinegar, but a very good substitute for 

 that useful article is often made by steeping successive 

 measures of the wood-ant in boiling water. The sub- 

 stance called chloroform owes its name to the similarity 

 between its constituent elements and those of Formic 

 acid. In chemical language, though not in chemical 

 formula, Formic acid consists of two atoms of carbon, 

 one atom of hydrogen, and two atoms of oxygen, 



