364 Miscellanies. 



MISCELLANIES. 



(rOREIGJV AND DOMESTIC.) 



JSfotices Extracted by Professor J. Griscom. 

 CHEMISTRY. 



1. Manganese. — Mode of ascertaining the commercial value of 

 its ores; 6?/ Edward Turner, M. D. Prof, of Chemistry in the 

 University of London. — The method of manipulating is as follows : — 

 About ten grains of the ore, in fine powder, are introduced into a flask 

 capable of containing about an ounce of water, and into its neck is 

 fitted, by grinding, a bent tube, about two inches long, which conducts 

 the chlorine from the flask into a tube about sixteen inches in length, 

 and five eighths of an inch wide, full of water, and inverted in a 

 small evaporating capsule, employed as a pneumatic trough. The 

 apparatus being adjusted, the flask is half filled with concentrated 

 muriatic acid, the conducting tube instantly inserted, and heat applied 

 by means of a spirit lamp. The air of the flask together with the 

 chlorine is then collected, the greater part of the latter, if the gas is 

 not very rapidly disengaged, being absorbed in its passage ; and con- 

 sequently the receiving tube, at the close of the process, will be about 

 half full of gas. When the ore is completely dissolved, the last traces 

 of the chlorine are expelled from the flask by muriatic acid gas. In 

 order that the chlorine thus collected may be entirely absorbed, the 

 aperture is closed by a ground stopper, or still more conveniently by 

 the finger, and the gas is well agitated until the chlorine is wholly ab- 

 sorbed. As the solution in the inverted tube may become too satu- 

 rated to dissolve all the chlorine, it is convenient to fill a pipette with 

 pure water, and with the aid of the mouth, force a current to ascend 

 into the tube, and thereby cause the heavier solution to flow out into 

 the capsule. 



The absorption being complete, the solution of chlorine is intro- 

 duced into a six or eight ounce stoppered bottle, and a dilute solution 

 of green vitriol, made, for example, with a hundred grains of the 

 crystallized salt and a pint of water, is added in successive small 

 quantities until the odor of chlorine just ceases to be perceptible. 

 The quantity of liquid required for the purpose may be conveniently 

 measured in a tube about sixteen inches long, and three fourths of an 



