234 THE INCOME OF ENERGY 



Sugar disappears from the blood on stand- 

 ing. 



It has been found by Le*pine and Barral 1 that 

 the glycolytic power of the blood increases as the 

 temperature rises to 52.5 C., which is the opti- 

 mum. At 54 the ferment is destroyed. 



Oxidation not Dependent on Living Cells of Blood. 

 - Place the following solutions at 34-35 G. for 

 six hours, allowing a stream of air to pass through 

 the liquid. Then estimate the sugar. 2 



A. Calf s blood 100 c.c. 



Water containing 1.14 gram grape sugar 10 c.c. 

 Seegen 3 recovered 1.000 gram. 



1 Lepine and Barral : Comptes rendus de I'academie des sci- 

 ences, Paris, 1891, cxii, p. 146. 



2 Test the filtrate by adding a drop of acetic acid and a little 

 ferrocyanide of potassium. 



The absence of a precipitate shows freedom from proteids and 

 ferric salts. Concentrate nitrate to 150-200 c.c. 



Titration of the Sugar Extract. Make the volume of the 

 solution such that its probable content of sugar shall lie 

 between 0.0004 and 0.0010. Causse (Bulletin de la Societe 

 chimique de Paris, 1, p. 625) recommends that 1750 c.c. of 

 water containing 5 grams of ferrocyanide of potassium be added 

 to each 250 c.c. of Fehling's solution. Boil 10 c.c. of this 

 mixture and add the sugar solution drop by drop until the blue 

 liquid is decolorized (Arthus : Archives de physiologic, 1891, 

 p. 425). 



3 Estimation of Sugar in Blood. Extraction of the Sugar 

 from the Blood. To 350-400 c.c. boiling water add all at once 

 50 c.c. blood containing 5 c.c. one per cent acetic acid. Let 



