ZEA 185 



with a dilute solution of sodium carbonate, which neutralizes 

 the acid, and precipitates the dissolved iron, and coagulates 

 the colloidal albuminoids. The neutral liquor is then filtered, 

 first in bag filters, and then in bone-char filters. From the 

 first bone-char filters, there issues a light liquor. This is 

 evaporated to increase its concentration, and passed on as 

 heavy liquor to the bone-char filter again. The liquor that 

 results from this second filtering is boiled down in vacuum 

 pans, whence it comes as the finished glucose. 



Pure glucose syrup has httle flavor, and but half the sweet- 

 ness of cane syrup. Maize syrup is mixed with varying 

 quantities of cane syrup and sold as a substitute for golden 

 syrup and molasses. It is the basis of many manufactured 

 jellies and preserved fruits. 



Grape Sugar. — This is a crude sugar made from starch, 

 in a manner very similar to that employed in the manufac- 

 ture of glucose. However, hydrolysis is more complete, the 

 process of conversion being carried to the point that no dex- 

 trin is precipitated when a sample is placed in strong alcohol. 

 Grape sugar appears on the market as a hard, waxy solid. 

 It finds considerable use in the manufacture of sparkling 

 ales; and, also, as a reducing agent in indigo dyeing, and other 

 industries. 



Artificial Gums. — These are known as dextrins and British 

 gums, and are made from starch. Starch is heated to a 

 temperature varying from 170 to 2'jo°C. During this proc- 

 ess, the starch may be treated with dilute nitric acid to bring 

 about hydrolysis, although if high temperatures are used, 

 the addition of acid is unnecessary, as the starch itself con- 

 tains enough acid and water to effect hydrolysis. Dextrins 

 and British gums are used on envelopes and postage stamps, 

 and also in many of the textile industries. 



Stock Food. — Corn fodder includes the whole plant — stalks, 



