CRYSTALLIZATIONS. 



113 



were more or less broken, on account of the fragile nature of the ashy film ; but 

 many were preserved entire, and exhibited in the field of view, the crystalline 

 network of the figure. With- Fjrr M 



in the compartments formed 

 by the chains of crystals, dark 

 masses are beheld, which are 

 crystals of a larger size. The 

 small crystals measure in 

 length one-two thousandth part 

 of an inch, and the larger one- 

 seven hundred and seventy - 

 fifth part of an inch. 



Amid the starch globules of 

 potatoes and in the outer coat 

 ing of the bulb of the onion, 

 crystals have likewise been n 

 found, differing in form from 

 all the preceding. In figure 182 

 the thin coating of an onion is 

 delineated as it appears when 

 magnified. This tissue is di 

 vided up into cells in which 

 the crystals are formed. Their shape is that of a right square prism, and, in 

 length, they measure one-eight hundred and thirtieth part of an inch. 



Fig. 182. 



