0)1 Alcohol at common Temperatures. 49 



The conversion of nialeie acid into carbonic acid and lactid has 

 not yet been realized, nevertheless it follows from the experi- 

 ments of Engelhardt that lactid is intimately connected with 

 these acids. On distilling lactic acid, he obtained citraconic acid; 

 but the latter is homologous with maleic acid, from which, accord- 

 ing to the above equation, the lactid ought to be formed. 



CnPO* = CMP 03 + HIIO 



Ghoxylic 

 acid. 



C4H606 



Tartaric 

 acid. 



Auhydrous 

 glyoxylic acid. 



= C^ H^ 0^ 



+ IIHO 



C^H^O^ - C02 = CIl^O 



Anhydrous 

 glyoxylic acid. 



C^ H-i 0^ 



Anhydi'ous 

 tartaric acid. 



CO^ 



C3 H"* 03 



, ' 



Pyroracemic 

 acid. 



The chief character of the decompositions of these acids is to 

 part with water and carbonic acid. This peculiarity is explained if 

 it is assumed that they originate from the radical (Gly) =C^ H^O^, 

 or substances polymeric with it, combining with water, or oxygen 

 and water. According to Berthelot, from carbonic oxide and 

 water formic acid is produced. The latter contains formyle, 

 C H 0, which is easily oxidized to water and carbonic acid. The 

 radical C^ H^ 0- is polymeric with formyle. 



The products of decomposition of malic, citric, and tartaric 

 acids, whether by fermentation or by caustic potash at a higher 

 temperature, are either oxalic oi- acetic acids, or substances be- 

 longing to the same series of compounds, viz. acetone and pro- 

 pyhc acid. The radical C^ H^ 0^^ is closely connected with oxalic 

 and acetic acids. If we add oxygen, it is converted into oxalic 

 acid, as in the case of glycolic and glyoxylic acid; and on addi- 

 tion of hydrogen, we get a substance containing the elements of 

 acetic acid : — 



C2 H2 0^ -f 02 = C'^ H^ 04 oxalic acid, 



C2 H2 02 + 112 = (^i 114 Q2 ^^j.^j^. jj^j J 



Quecnwood College, Dec. 1.5tli, 18.'>(). 



Phil. Mag. S. 1. Vol. 13. No. 83. Jmi. 1857. 



