DETERMINATION OF OXYBUTYRIC ACID 451 



dilute sulphuric acid, and then decomposing it by adding 

 drop by drop a solution of potassium bichromate. The oxy- 

 butyric acid undergoes decomposition according to the fol- 

 lowing formula, into diacetic acid, then into acetone, carbon 

 dioxide and water: 



CH, CH, 



I I CH, 



CH.OH CO 



I + O = H 2 + \ = H a O + CO, + CO 



CH 2 CH 2 I 



COOH COOH 



The acetone distilled over is taken up in water and the 

 proportion determined by Mes singer's method with iodine 

 and thiosulphate. J. Mondschein, 59 who worked out a 

 method in the author's laboratory by which the quantitative 

 estimation of oxybutyric and lactic acids is possible together 

 (vide infra), was able to fully satisfy himself of the delicacy 

 of SchafFer's method. 



So much may be said of the acetone bodies and their 

 physiological significance. 



69 J. Mondschein, 1. c. 



