Plate 138 
A. —Photomicrograph of the isolated “sand” crystals from some of the same ice 
cream used for Plate 137. Photographed with polarized light. X 90. 
B. —Photomicrograph of some pure recrystallized lactose hydrate from condensed 
whey. Photographed with polarized light. X 90. 
C. —Photomicrograph of a crystal of pure sucrose. Photographed in plane light. 
