202 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



The spring of the air in your flesh is also shown by this ex- 

 periment, the flesh of the inside of your hand swelling down- 

 wards within the exhausted glass. Price, 75 cents. 



The Bladder Glass. Cover the large end 

 of the last described receiver (Fig. 192) with 

 a piece of wet bladder, and leave it to dry. 

 After it is perfectly dry place the open end 

 on the pump-plate, and exhaust the interior 

 air till the weight of the air on the bladder 

 causes it to burst with a loud report. If, 

 instead of the bladder, a piece of sheet india 

 rubber is used, it will expand and fill the glass vessel. 



Price, 75 cents. 



Fig. 193. Bladder Glass with Cap and Stop- Cock. 



(Fig- 193.) This arrangement of the 

 bladder glass when attached to a flexible 

 tube, and connected with the air pump, 

 admits of its being turned in any direction, 

 and may be seen by a large audience to 

 more advantage than when used on the 

 pump plate. It may also be used to show 

 the expansion of air, by closing the stop- 

 cock, and placing under a receiver, when 

 the bladder will be forced out, and if the 

 exhaustion be continued, it will be broken 



by the expansive force of the air within the glass. 



The experiment may be varied by using a piece of sheet 



india rubber, which will not be broken, but swell out, or 



be drawn in, as the instrument may be used. 



Price, $2.00, 



Fig. 194. Apple Cutler. (Fig. 194.) This consists of 



a metallic cylinder, or cone, open at each end, 

 having a base ground true, and fitting air tight 

 the pump plate, and at its upper end a sharp 

 edge. To use, place the cone on the air pump, 

 an apple on the top of the cone, and exhaust 

 the air ; the pressure of the air on the outside 

 of the apple will cause the apple to be cut, and 

 forced through the opening. 



Price, $1.50. 



