VEGETABLE POWDERS 



183 



Fig. 2. GUM ACACIA. INDIA GUM. a, a water mount of the powdered 

 fragments of true gum acacia show a typical conchoidal fracture with absolutely 

 smooth surfaces, b, the fragments of India gum mounted in water show typical 

 conchoidal fracture but the surfaces are characteristically wrinkled. These 

 observations must be made as soon as the mounts are made as both gums soon 

 dissolve in water. 



