286 SUGARS [CH. XIII 



'reducing power' after complete 'inversion/ i.e. inversion 

 with 2 p.c. hydrochloric acid. 



To invert with citric acid add 5 grs. of solid crystallised 

 acid for every 100 c.c. of the solution and heat on the 

 water-bath for one hour under a reflux condenser; then 

 exactly neutralise and if necessary make up to the original 

 or some definite volume. 



For complete inversion add to the solution sufficient 

 hydrochloric acid to make 2 p.c. of acid and heat on the 

 water-bath for three hours under a reflux condenser ; then 

 exactly neutralise, etc. as after inversion with citric acid. 



The determinations of ' reducing power' in (1) (2) and 

 (3) should be made as accurately as possible. 



[It is convenient to state results in 'grs. glucose per 

 100 c.c. of solution/ meaning that 100 c.c. of solution has 

 the same reducing power as would be possessed by a 

 solution containing so many grs. glucose.] 



The calculation is easy when the method is thoroughly 

 understood. 



The reducing power is stated in grs. glucose in each 

 case per 100 c.c, of solution. 



Original reducing power = a. 



Reducing power after inversion with citric acid = b. 



Reducing power after inversion with hydrochloric 

 acid = c. 



b a = glucose from inverted cane-sugar. 



.*. (b a) x '95 = cane-sugar. 



c 6 = glucose corresponding to increased reducing 

 power of maltose inverted. 



/. (c - 6) x 2-32 = maltose. 



