PHYSIOGRAPHY. 



Oxygen. 



Hardness, may be kneaded between the fingers like dough 

 Sp. gr. = 0-955 . . . 0-970. 



1. It melts in the flame of a candle, into a clear mass. It is rieithei 

 soluble in alcohol nor water, even when boiling, and but slowly so, ir 

 ether and spirits of turpentine. It burns like wax with a soft cleai 

 flame, and on being extinguished, diffuses an agreeable odor. 



2. It occurs at Slauik in Moldavia. 



OXYGEN. Pure Oxygen-Gas. 

 Gaseous. Transparent. 

 Sp. gr. =1-1111. 



1. Oxygen-gas is a powerful supporter of combustion. A freshly 

 extinguished taper introduced into a small vial of it, is immediately re- 

 kindled with a slight explosion ; and iron-wire, on being previously 

 heated, burns in it, with brilliant scintillations. It is wholly free from 

 odor and taste. 



2. The evolution of oxygen from vegetables, its only natural source, 

 depends upon the influence of vitality. The carbonic acid they absorb 

 is decomposed, the carbon appropriated by the plant, while this species 

 is set at liberty. Its emission from vegetables may be detected by ex- 

 posing a healthy mint of some kind, in a bell-glass of water over a pneu- 

 matic cistern to the sun of a summer's day: the oxygen-gas will collect 

 in the upper part of the receiver, and may be transferred to a convenient 

 vessel, and tested in the usual manner. 



PARANTHINE. (See Scapolite.) 

 PARGASITE. (See Hornblende.) 

 PAULITE. (See ITypersthene.) 

 PEARL-GLIMMER. (See Margarite.) 

 PEARLSPAR. (See Dolomite.) 

 PEARLSTONE. (See Pitchstone.) 

 PECTOLITE. 



In spheroidal masses : composition columnar, diverging. 

 Lustre vitreous to peaily. Color white, yellowhh or greyish. 

 Hardness, between Fluor and Feldspar. Sp. gr. = 2-69. 

 1. Before the blow-pipe, it yields a white, transparent glass. After 

 having been calcined, it forms a jelly in muriatic acid. 



