STARCH. 



49 



Starch is insoluble in cold water, but forms with boiling 

 water a paste in which all traces of structure are lost. If a 



specimen of starch be gently heated with water upon a glass 

 slide, the granules will be seen to swell at a temperature of 



40-f>0 C., and the appearance of stratification will often be- 

 come plainer. The alkalies and mineral acids generally hasten the 



FIG. 26. Starch-granules of wheat. FIG. 29. Starch-granules of oats. 



Fio. 27. Starch-granules of Indian corn. FIG. 30. Starch-granules of rice. 



FIG .28. Starch-granules of barley. Fio. 31. Starch-granules of potato. 



FIG. 32 Starch-granules of Maranta (arrow-root) 



FIG. 33. Starch-granules of Boroaria I'Chilt arrow-root). 



Fio 34 Starch-granules of Vicla sativa, var. leucosperma. All the figures of 

 starch are from Berg and Schmidt. 



4 



