40 Dr. Debus on the Action of Nitric Acid 



on the water-bath to the consistency of a thick sjTup. This 

 residue consisted of glycolic, glyoxylic, and oxalic acids, and of 

 a member of the same class of compounds to which the aldehyde 

 of acetic acid belongs. It was dissolved m water and neutralized 

 with carbonate of lime. On addition of alcohol, the glycolate 

 and glyoxylate of lime precipitated almost entirely, whilst the 

 aldehyde remained in solution. The filtrate from this precipitate 

 was evaportcd on the water-bath ; the aldehyde remained as a 

 thick synip of a slight brown colour. It was soluble in aether, 

 except a small quantity of brown resinous matter. The setherial 

 solution left, after filtration and distillation at 100° C, a solid, 

 transparent, and amorphous substance of a slight yellow colour. 

 This residue consisted almost entirely of the aldehyde of gly- 

 oxylic acid; I propose to call it Ghjoxal, C^H'*0^*. It is iso- 

 meric with glycolic acid, and bears the same relation to glyoxylic 

 acid as the aldehyde C- H'' to acetic acid. 



The strong aqueous solution of this substance was mixed with 

 five or six times its bulk of a concentrated solution of bisulphite 

 of soda. After about three hours' standing, a large quantity of 

 crj'stals formed around the sides of the bottle in which the mix- 

 tmre was kept. 



These crystals were dissolved in as little boiling water as pos- 

 sible, and the clear liquid allowed to cool gradually. Prismatic 

 crystals of a compound of 



Glyoxal ivith bisulphite of soda, 2(NaH0 . SO'^), C^H^O^, 



were obtained. From the mother-liquor, on addition of alcohol, 

 another quantity of the same substance precipitated, which, 

 if not quite pure, was recrystallized in the same manner. This 

 compound forms white and hard crystals, easily soluble in 

 water, but almost insoluble in alcohol. The aqueous solution 

 tui'ns slightly yellow on continued boiling ; it precipitates ace- 

 tate of lead and chloride of barium. Hydrochloric and diluted 

 sulphuric acids decompose it very slowly, generating sulphurous 

 acid. Nitric acid oxidizes very rapidly the bisulphite of soda 

 into bisulphate, and the glyoxal into oxalic acid. 

 Analysis gave the following results : — 



I. 0625 grm., burnt with chromate of lead, gave 0"1935 grm. 

 carbonic acid and 0'122 grm. water. 



0'622 grm. gave 0"311 grm. sulphate of soda. 



II. 0-8825 grm. gave 0*2735 grm. carbonic acid and 0-1730 

 grm. water. 



0-478 grm. gave 0-237 grm. sulphate of soda. 



0-729 grm., oxidized with a mixture of chlorate of potash and 



* C=12, H=l, 0=Hi. 



