STARCH. 85 



which may be diffused in the water, but does not 

 form a true solution. This paste gives the same 

 reaction as unaltered starch. Solutions of chlo- 

 ride of calcium, chloride of zinc, potassic hydrate, 

 and concentrated iodide of potassium, as well as 

 the mineral acids, carbolic acid, acetic acid, and 

 trichloracetic acid cause this conversion of starch 

 into paste in varying degrees, depending upon their 

 concentration. The beginning of the change may 

 always be recognized by the more evident stratifi- 

 cation of the grains. Dilute chromic acid produces 

 this effect in a marked degree, and has been used 

 to demonstrate stratification in the peculiar starch 

 bodies which are found in the latex of Euphor- 

 biaceae. 



Alcohol has an opposite effect, the stratification 

 often completely disappearing under its action. 

 Cuprammonia causes the grains to swell, and colors 

 them pale blue, but it does not change them into 

 paste. 



For directions for demonstrating the starch 

 in chlorophyll bodies the reader is referred to 

 page 7. ' 



1 Crie announces a new substance found by him in the asci of Sphaeria 

 Desmazierei, Berk., which he calls amylomycin, and which is said to have 

 the same reaction as starch. (Comptes rendus, T. LXXXVIII., pp. 759, 

 985.) We mention this here merely to make our account complete. The 

 substance is so insufficiently characterized by its discoverer that one may 

 be pardoned some doubts as to its independent nature. 



