VII. SITEPSICS. 



The present class embraces arts which are exclusively con- 

 fined to the preparation of food, or which prepare substances 

 largely used in the preparation and preservation of food, 

 both solid and liquid, and likewise used in the arts generally. 



1. Preparation of Farina and Sugar. 



Flour, starch, and sugars, are employed both as food and 

 m the arts. 



1. Starch is extracted from roots, as the potato, arrow-root, 

 or from grain, wheat, rice, corn, by washing over and collect- 

 ing the finely suspended sediment. There are difierent kinds 

 of starch, but even the same kind, as that obtained from the 

 above-named substances is supposed to be, differs in its pro- 

 perties so far that it is desirable to distinguish one from the 

 other. The form of the grain under a powerful microscope 

 is one mean of distinguishing them, and probably the best. 



Starchy Wheat and Potato. — Redwood has given the follow- 

 ing method of distinguishing them. If wheat-starch be ground 

 well in a mortar with water, then filtered, and the filtrate 

 tested with tincture of iodine, it strikes a yellow or reddish, 

 but not a blue color, whereas potato-starch, similarly treated, 

 strikes a blue color. 



Instead of soda-ash liquor to steep grain in, it is proposed 

 to use quicklime and salt. (Lond. Journ. xxxvi. 391.) 



Amidulm. — Schulze applies this name to a substance of 

 the same elementary composition with starch, and forming the 

 transition substance preceding all the transformations of starch 

 into dextrin. It is perhaps identical in composition with 

 Jacquelin's amylum granules ; is soluble in hot and insoluble 

 in cold water, and reacts with iodine like starch. (Journ. fur 

 Prac. Chem. xliv. and Ch. Gaz. vi.) 



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