CH. XIIl] QUANTITATIVE. 269 



a — (maltose x '62) = glucose. 



[The numbers used above are obtained from these data : 

 342 grs. CiaHsjOii give 360 grs. CsHiaOs on inversion. 

 .•. glucose X "95 = cane-sugar or maltose. 

 1 gr. maltose has same reducing power as "62 grs. 



glucose. 

 1 gr. maltose gives 1"05 grs. glucose on inversion. 

 .•. 1 gr. maltose on inversion gives increased reducing 

 power = "43 grs. glucose (1.05 — '62). 



.•. increase of glucose by inversion of maltose 



X 2'32 = maltose.] 

 An actual example will illustrate use of the above. 

 100 c.c. of an extract. 



(a) reduced 30 c.c. of Fehling. 



(6) after inversion with citric acid and neutralising, 

 38 c.c. Fehling. 



(c) after inversion with hydrochloric acid and neu- 

 tralising, 45 c.c. Fehling. 

 (10 c.c. Fehling = '05 grs. glucose.) 

 Then 6-a = 38-30 = 8 c.c. Fehling = -04 grs. glucose. 

 .'. cane-sugar = '04! x "95 = "038 grs. 

 c— 6 = 45 — 38 = 7 c.c. Fehling = 'OSo grs. glucose. 

 .-. maltose = -035 x 2-32 = -081 grs. 



a = 30 c.c. Fehling = "150 grs. glucose. 

 .'. original glucose = "150 grs. —('081 x "62) 

 = •1 gr. 



