516 SCIENTIFIC RECORD FOR 1884. 



the results of new experiments to determine whether the use of glucose 

 is injurious to health. 



There are twenty-nine factories of starch-sugar in the United Siates, 

 using, as nearly as can be estimated, 43,000 bushels of corn per day. 

 yielding products of the annual value of nearly $10,000,000. In Ger- 

 many the industry is an old one ; in 1881-'82 there were thirty- nine 

 factories, consuming over 70,000 tons of starch and producing about 

 40,000 tons of starch-sugar. 



The products are of various grades, appearing in commerce under the 

 following names: (A) Liquid varieties: Glucose, mixing-glucose, mixing- 

 siruj), corn sirup, jelly-glucose, confectioners' crystal glucose. (B) The 

 solid varieties: Solid grape-sugar, clipped grape-sugar, granulated grape- 

 sugar, powdered grape-sugar, confectioners' grape-sugar, brewers' grape- 

 sugar. The process of manufacture consists, first, in extracting the 

 starch from the corn in a state of sufficient purity, then transforming this 

 into sugar by treatment with dilute acid, and subsequently neutralizing 

 the acid, purifying, and concentrating the product. The steps in the ex- 

 traction of starch are steeping, grinding, mechanical separation, cleans- 

 ing, collecting, and washing. A bushel of corn weighing 56 pounds 

 yields, on theaverage,30poundsof starch, 14 pounds of cattle food, and 12 

 pounds of waste. The transformation of the starch into sugar, termed 

 conversion, is effected in either open or closed converters ,• the former are 

 wooden vats of 3,000 to 4,000 gallons capacity, the latter are copper 

 vessels furnished with safety-valves and capable of withstanding a 

 pressure of six atmospheres. The acid used is usually sulphuric, and 

 the quantity employed varies with the object of the manufacturer, the 

 liquid product requiring less acid than the solid j the proportion varies 

 from one half pound oil of vitriol to 1^ pounds per 100 pounds of starch. 

 In the open converter the starch and acid liquid are boiled until the 

 iodine test ceases to give a blue color, which usually requires about four 

 hours. In the closed converter less time is required, since the pressure 

 is raised to 45 to 75 pounds per square inch. 



The sulphuric acid is then neutralized with marble-dust, and the sul- 

 phate of calcium removed by filtering through bags of cotton cloth or 

 filter-presses. The liquor is next passed through bone-black filters, 

 concentrated in vacuum-pans, and further purified. The liquid and 

 solid varieties receive different treatment in the final stage. 



Both glucose and grape-sugar find extensive application for a great 

 variety of purposes as substitutes for cane-sugar or for barley. The 

 most general purposes for which starch-sugar is used are (1) for the 

 manufacture of table sirup; (2) as a substitute for barley malt in brew- 

 ing ale or beer; (3) as a substitute for cane-sugar in confectionery; (4) 

 for the adulteration of cane-sugar, to which it is added to the extent of 

 20 per cent, or more; (5) for the manufacture of artificial honey; (G) in 

 the manufacture of vmegar; (7) in the manufacture of liquor-coloring, 

 and in many minor applications, such iis in cooking, in prej)aration of 



