SUPERIOR ANIMALS. 159 



instrument imagined by Fran9ois Arago. Now, in 

 the case of the phosphorescence of Schistotega o,<?- 

 mundacea, spoken of in the second part of this 

 work, and those cases alluded to here, it would be 

 easy to ascertain whether the light was transmitted 

 directly from the plant or the animal itself, or owed 

 to the reflection of diffused daylight, as we observe 

 on the spiders' -webs in a semi-obscurity. Very 

 simple polariscopes, consisting of plates of crystal 

 inserted into flat pieces of cork, are sold by some 

 of the opticians of Paris ; whenever reflected light 

 is observed, at certain incidences, through this 

 simple apparatus, it shows coloured stripes, owing 

 to the polarization of the reflected light. With 

 directly transmitted light these coloured bands 

 are not visible. 



A very remarkable case of phosphorescence was 

 witnessed by Dr. Kane in his last voyage to the 

 Polar regions, and described in his journal under 

 the date January 2nd, 1854. He was on his way 

 with Petersen to an Esquimaux settlement, in 

 order to procure food. Their thermometer was 

 at -42 Centigrade (-44 Fahr.). With their 

 weary dogs and sledge they had reached some un- 

 tenanted huts at a place called Anoatok, after 

 thirty miles' march from the ship : (( We took to 

 the best hut/' says Dr. Kane, " filled in its broken 

 front with snow, housed our dogs, and crawled in 

 among them. It was too cold to sleep. Next 



