CH. XIIl] DEXTRINS. 265 



(3) Heat another part with dilute hydrochloric acid 

 and ascertain whether the 'reducing power' has been 

 further increased or not, i.e. if the value obtained for the 

 ' reducing power ' is greater than that obtained in (2). 



Since cane-sugar only is inverted by citric acid and 

 both cane-sugar and maltose by hydrochloric acid, it 

 follows that an increase in (2) indicates the presence of 

 cane-sugar, and a further increase in (3) that of maltose. 



The exact details for performing these experiments 

 are given in the next section under quantitative exami- 

 nation — for qualitative evidence rough estimations will 

 suffice. 



If the presence of cane-sugar and maltose is indicated 

 as above, attempts should be made to obtain crystals of 

 the cane sugar and an osazone of the maltose. 



To obtain crystals of the cane-sugar add, to a portion 

 of the solution, strontia-water Sr(0H)2 in considerable 

 quantity and filter; evaporate down the filtrate till a 

 precipitate (yellowish amorphous masses) begins to 

 separate out, and let it stand for some time. Collect 

 the precipitate, suspend in dilute alcohol and decompose 

 with a current of CO2; filter, concentrate the filtrate if 

 necessary, and add strong alcohol till it just begins to 

 cause turbidity. Stir in a small crystal of solid cane- 

 sugar and allow it to stand. 



To obtain maltosazone from maltose in presence of 

 glucose, evaporate the solution to small bulk and add 

 phenyl-hydrazin and sodium acetate as in testing for 

 glucose. Heat on the water bath for one hour with reflux 

 condenser, and allow the products to stand in the cold for 



