FORMIC ACID. 7 



rytes, equivalent to 55*91 of barytes. From this analysis, Lie- 

 big concludes that the salt was composed of 



1 atom mesoxalic acid, . 6 '25, or per cent 37*04 

 1 atom barytes, . . 9'5, ... 56-30 



1 atom water, . 1-125, ... 6-66 



16-875 100-00 



It is easy to see how mesoxalic acid results from the decompo- 

 sition of alloxanic acid. 



Hydrous alloxanic acid is . C 8 H 4 Az 2 O 10 



Subtract 1 atom urea, C 2 H 4 Az 2 O 2 



Remain 2 atoms mesoxalic acid, C 6 O 8 



SECTION II. OF FORMIC ACID. 



An account of this acid has been given in the Chemistry of In- 

 organic Bodies, ii. 58, and the Chemistry of Vegetables, p. ] 7. 



It is secreted by the Formica rufa or red ant, and is the liquid 

 that renders the bites of these insects so painful. It was first 

 publicly noticed by Mr Ray in the year 1670.* Dr Hulse had 

 written him that he had found this passage in Lang ham's Gar- 

 den of Health, " Cast the flowers of cichory ( Cichorium Intybus) 

 among a heap of ants, and they will soon become as red as blood." 

 He mentions that the fact had been observed before by various 

 individuals, among others by John Bohin. Dr Hulse said that 

 he had tried the experiment and found it to succeed. Mr Fisher 

 had stated to Mr Ray several years before, that, " if you stir a 

 heap of ants so as to rouse them, they will let fall on the instru- 

 ment you use a liquor which, if you presently smell to, will twinge 

 the nose like newly distilled oil of vitriol." Mr Fisher farther 

 stated, that, " when ants are distilled by themselves or with wa- 

 ter, they yield a spirit like spirit of vinegar, or rather like spirit 

 of viride aris." It dissolves lead and iron. When you put the 

 animals into water, you must stir them to make them angry, and 

 then they will spirt out their acid juice." Margraaf obtained this 

 acid in 1749, by distilling ants mixed with water and rectifying 

 the liquid, which came over. The acid obtained had a sour taste 

 and smell. It combined with potash and ammonia, and formed 

 crystallizable salts with both. It did not precipitate nitrates of 



* Pail. Trans, v. 2063, or Abridgement, i. 554 



