OBJECTS FOR THE POLARISCOPE. 225 



SECTIONS OF QUARTZ 



give infinite variety and arrangement of colour. 



The following list of objects are specially for the polar- 

 iscope, and may be obtained at Baker's and at other opti- 

 cians : 



Sections of bone. 

 Hairs of animals. 

 Hairs from plants. 

 Fibres of Palm. 

 Section of Vegetable Ivory. 

 Papyrus. 



Palates of Whelk. 

 Sections of Marble. 



Granite. 



Agate. 



Foot of Wasp. 

 Elytra of Beetle. 

 Section of Cuttle-fish bone. 

 Crystals of Borax. 

 Salicine. 



Cellularia (Zoophyte). 

 Gemellaria (Zoophyte). 

 Sections of Infant Skull. 

 Section of Tooth.. 



Crystals of lodo-disulphate of Quinine. 

 Oxalate of Ammonia. 



15 



