356 THE AMERICAN MONTHLY [Nov., 



Red Squirrel 320 



Black Bear (100 meas) 320 



Star-nosed Mole 338 



Weasel 338 



Rat 284 



Skunk 284 



Chipmunk 284 



Chipmunk 248 



Ass 320 



Hog 284 



Little brown Bat 284 



Raccoon 284 



Cat 266 



Cat 267 



MEDICAL MICROSCOPY. 



Hydrogen Dioxide. — This remarkable liquid which con, 

 tains the greatest percentage of oxygen of any compound known 

 was, for sometime, considered as a mere solution of oxygen in 

 water, and consequently was called oxygenated water. It was 

 afterward obtained free from water and found to be a definite 

 chemical compound of hydrogen and oxygen, and differing from 

 water in containing twice as much oxygen. In this state it is a 

 heavy, oily liquid, readily decomposed at ordinary temperatures - 

 but if heated, with explosive violence, being converted into ord, 

 jnary water and oxygen gas. When poured into water it sinks, 

 being nearly half again as heavy as that liquid, but is miscible 

 in all proportions with it. It has a somewhat bitter, astringent 

 taste, and is colorless, transparent and without odor. It bleaches 

 the skin, hair, ivory and destroys organic coloring matter, pus 

 and all organisms with which it comes in contact by liberating 

 oxygen gas in a nascent or active state. 



The preparations found in commerce are only solutions of 

 this compound in water, and sold in different degrees of concen- 

 tration or strength, rated by the number of volumes of oxygen 

 gas they can be made to yield. A fifteen volume solution is 

 one that will give off fifteen volumes of gas from one volume of 

 the solution. A ten volume solution will yield ten pints o- 

 oxygen gas from one pint of the solution, and so on. 



These solutions, although more stable than mere concentrated 

 •preparations, nevertheless decompose and lose their nascent 



