CH. XIIl] DEXTRINS. 283 



(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(OH)o 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 COo ; 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 



