SYNTHETICAL EE8EAECHES ON ACIDS OF THE LACTIC SEEIES. 337 



The acid of the third ether {diamyloxalic acid) is best prepared by decomposing the 

 ether with boiling baryta-water. After removing the excess of baryta in the usual 

 manner, baric diamyloxalate crystallizes on evaporation in minute elastic needles, 

 which, when dry, have the appearance of wool. It is moderately soluble in hot water, 

 but sparingly so in cold. Two determinations of barium in this salt gave the following 

 results : — 



I. •2139 grm. of baric diamyloxalate gave '0875 grm. baric sulphate. 

 II. •2155 grm. gave "0771 grm. baric carbonate. 



These numbers agree with the formula 



,Ho 



jCAy^] 

 C24H,eBa"06,or^^^Ba"; 

 IcAya Ho 



as shown by the following comparison of percentage numbers :- 



Experiment. 

 A 



^ 



I. n. Mean. Theory. 



Percentage of barium . . 24-11 24-83 24-49 24-16. 



If baric diamyloxalate be dissolved in hot dilute alcohol and excess of sulphuric 

 acid be added, the liquid after filtration contains diamyloxalic acid in solution. On 

 heating upon a water-bath, the alcohol gradually evaporates, and diamyloxalic acid 

 crystallizes in the hot solution as a beautiful network of brilliant silky fibres, which 

 after being well washed in cold water, and dried at 100°, yielded on analysis the 

 following numbers : — 



•1090 grm. gave "2658 grm. carbonic anhydride and -1103 grm. water. 



This result agrees well with the formula 



fCAygHo 

 Ho 



Gn^uO,,or^^^ 



Calculated. Found. 



A 



66-66 66-51 



11-11 11-24 



22-23 22-25 



100-00 100-00 



Diamyloxalic acid presents the appearance of colourless satiny fibres, which are inso- 

 luble in water, but soluble in alcohol or ether. This acid is remarkable for its high 

 melting-point, 122° C, in which respect it surpasses any of the acids of this series. Its 

 melting-point is very sharply defined, and it solidifies immediately on a very slight 

 reduction of temperature. Heated more strongly, it sublimes and condenses on a cold 

 surface in white crystalline flakes like snow. 



