184« Prof. Hare's improved Eudiometrical Apparatus. 



as the socket of the receiver of the eudiometer above de- 

 scribed. In lieu 

 of the igniting 

 wires employed 

 in that instru- 

 ment, a cup 

 containing phos- 

 phorus is sup- 

 ported by and 

 closes the upper 

 end of a tube T. 

 This tube is sol- 

 dered] into the 

 axis of a brass 

 plug, screwed in 

 at the bottom of 

 the brass cast- 

 ing, which at 

 top receives the 

 socket of the 

 spheroid. The 

 phosphorus be- 

 ing ignited by 

 means of a hot 

 iron passed up 

 through the tube, 



the oxygen of the air included in the spheroid is condensed, 

 and the deficit ascertained by the gauge. 



It will be recollected that the gauge of the barometer-gauge 

 eudiometer is graduated into 450 degrees. It is expedient to 

 commence this experiment with the mercury at 50 degrees, 

 which leaves 400 parts in the spheroid, and allows room for 

 the expansion which takes place in the beginning of the pro- 

 cess. 



I have made several experiments with this apparatus, and 

 find the results to harmonize with each other, and with those 

 obtained by my other instruments. 



Upon the wire W, which passes through the stuffing box 

 into the cavity of the spheroid, a copper hood is supported, 

 which is just large enough to cover the cap containing the 

 phosphorus. By this contrivance the phosphorus may be 

 secluded from the air, until its exposure becomes desirable. 



On one side of the spheroid a thermometer maybe observed, 

 which is so fastened by means of a stuffing-box, as that the 

 bulb is within, while the stem is without, and may be easily 

 inspected. A small sliding band enables the operator to mark 



the 



