COMPOUND PRODUCTS. CHAP. I. 

 SECTION III. 



Starch. 



Prepara- IF a quantity of wheaten flour is made into a paste 

 with water, and kneaded and washed under the ac- 

 tion of a jet till the water runs off colourless, part 

 of it will be found to have been taken up and to be 

 still held in suspension by the water, which will by 

 and by deposit a sediment that may be separated by 

 decantation. This sediment is starch, which may 

 be obtained also immediately from the grain itself 

 by means of a process well known to the manufac- 

 turer, who renders it finally fit for the market by 

 washing and edulcorating it with water, and after- 

 wards drying it by a moderate heat. 



Properties. Starch in this state is a fine and white powder 

 without any palpable taste or smell, of which the 

 particles often adhere in considerable masses, but 

 are easily divisible by the touch. If thrown upon 

 water it swims for a time upon the surface, and 

 seems to resist its moistening power, but mixes with 

 it at last, and forms, with cold water, a kind of 

 emulsion, and with boiling water, a thick paste. 



When thrown upon red hot iron it burns with a 

 kind of explosion, and leaves scarcely any residuum 

 behind. It has been found by the analysis of 



Cocnposi- Messrs. Gay Lussac and Thenard, to be composed 

 of carbon, oxygene, and hydrogene, in the following 

 proportion : 



tion. 



