866 Dr. Debus on the Action of Nitric Acid 



0-642 grm., dried in vacuo, lost at 120° C. 0-0495 grm. 

 water, corresponding to 7-71 per cent. 



If the above formula is multiplied by two, and three atoms of 

 water of crystallization added, 7*45 per cent, should be obtained 

 according to calculation. 



It is apparent that the composition of this substance, dried at 

 120° C, is nearly the same as that of glyoxylate of lime, — 



3(C* H8 Ca 0^) H-2H = C« W Ca^ Oi«=2(C2 H^ Ca O^) 



'^ ' +C2H8Ca03-}-H«0. 



Glyoxylate of lime. 



In order to check the analysis, the double salt was boiled with 

 lime-water. It was decomposed, and its glyoxylate of lime con- 

 verted into oxalate and glycolate of lime. Ill parts of glyoxy- 

 late of lime should yield 64 parts of oxalate or 50 parts of car- 

 bonate of lime. If, therefore, the formula 



2(2(C2 H3 Ca 04) + C« H^ Ca 0^ + H^ O) + SH^ 



represents the composition of this compound, it should yield, after 

 boiling with caustic lime, and conversion of the oxalate of lime 

 into carbonate, 27'6 per cent, of the latter. 



0-362 grm., dried in vacuo, gave 0*094 grm. Ca^ CO^, or 

 26-2 per cent. 



If the unstable character and the great difficulty of preparing 

 this double salt in a pure state be taken into consideration, then 

 both numbers seem to agree as well as could be expected. 



Glyoxylic Add, C^ H^ 0^. 

 In order to obtain this acid, its lime-salt is dissolved in water 

 and oxalic acid added as long as a precipitate of oxalate of lime 

 is formed. After filtering, the clear liquid is evaporated in vacuo. 

 The glyoxylic acid remains as a thick transparent syrup. It 

 absorbs in this state moisture very rapidly from the air, and dis- 

 solves easily in water. The solution neutralizes potash and soda, 

 and decomposes the carbonic acid compounds of all bases very 

 rapidly. Oxide of silver is partly dissolved and partly reduced 

 to metallic silver. The solution of glyoxylic acid, exposed in a 

 retort to a temperature of 100° C, loses first water, and then 

 the acid itself distils slowly over. It could not be obtained in 

 a solid state. Heated in a test-tube by the flame of a common 

 spirit-lamp, it boils, emits white fumes, and evaporates almost 

 entirely without turning black. 



Glyoxylate of Potash, C^ H^ Ka 0*. 



To glyoxylic acid is added a solution of carbonate of potash 

 till about three quarters of the acid are neutralized. The liquid 

 is then evaporated in vacuo until it yields with alcohol a copious 



