16 



PROFESSOR CONNELL ON A 



B is a small mercurial thermometer, the bulb of which reaches within f of an 

 inch of the bottom of the bottle, and the upper part of the bulb is on a level with 



the surface of the liquid contained in the bottle, or a little above that level. The 

 bulb ought not to be entirely immersed in the liquid. Its shape is an elongated 

 cylinder, about § inch in length, and about | in diameter. The thermometer has 

 a small scale attached to it, graduated according to both Fahrenheit's and Celsius' 

 scales from 0° F. to 100 D F. The stem of the thermometer is cemented at C into a 

 little brass stopper, fitted by grinding into the neck of the bottle, so as to be per- 

 fectly air-tight. DE is a small exhausting syringe of brass, the cylinder of which is 

 5 inches long, by about *$ inch wide. It must effect its purpose of exhausting in as 

 perfect a manner as an instrument of that size can accomplish. FG is a clamp of 

 brass, capable of being attached by the screw horizontally to a window-sill in the 

 position which it occupies in the figure, or vertically to a common table, the holding 

 surfaces which come in contact with the body grasped being well roughened. 

 The syringe screws into this clamp at K by a projecting screw soldered to the 

 former, when the clamp is screwed to a window-sill, as in the case when an ob- 

 servation is made at an open window ; or this projecting screw is inserted at L, 

 when the clamp is fastened to a table, as is done when the experiment is made in 

 a room. In both cases the syringe itself occupies a horizontal position, and 

 the bottle and thermometer, of course, a vertical one; the projecting screw K 

 should be so constructed as to cause the syringe to incline with the bottle a little 

 downwards, that the tendency of any ether to pass from the bottle into the 



