96 Dr. Schafhaeutl on the Circumstances under >which 



was then repeated as before, but no trace of electricity could 

 be discovered. 



After the greater part of the water had been evaporated 

 the boiler was opened, the deposited salt removed, and after 

 being well washed filled again with distilled water. After the 

 steam had reached a pressure of 31 inches, as in the first in- 

 stance, the stop-cock was again opened as before, and the 

 jet of steam was directed against the inside of the glass bell 

 in all its varied positions, but the gold leaves of the con- 

 denser remained motionless, or when positively electrified had 

 a tendency to collapse. 



I was obliged to fill the boiler again, and now took care to 

 have the same quantity of water as in the first experiment. 

 On the second trial the gold leaves separated again. On the 

 third trial the jet of steam touched the outside as well as the 

 inside of the glass bell. The fourth succeeded as in the first 

 experiment, and afterwards no effect could be produced. 



The boiler was again filled, and as I thought I had ob- 

 served that the gold leaves separated only when the steam 

 issued from the jet with a peculiar rushing fluttering noise, 

 quite different from the hissing sound which generally accom- 

 panies the escape of pure steam, I therefore directed my par- 

 ticular attention to it in this experiment. 



The water was at the height of about 1^ inch, and as soon as 

 the mercurial column had reached 32 inches I opened the stop- 

 cock with one hand, bringing with the other hand the axis of 

 the glass bell in the direction of the jet of steam. The rush- 

 ing sound was immediately observable, and the condensed 

 water streaming from the edges of the bell, the gold leaves 

 separating at the same moment to their extreme angle. After 

 I had discharged the disc of the electroscope the leaves again 

 opened several degrees, which happened likewise the third and 

 fourth time, as often as the vibrating bell came into contact with 

 the wires. The wetted interior of the bell had, therefore, not 

 only obtained, but also retained, a small charge long after the 

 steam had ceased to flow, and I was now able to produce the 

 desired effect as often as I pleased, the success depending en- 

 tirely on that state of the escaping steam which causes the 

 rushing or fluttering noise which happened only when the 

 boiler was filled at about \l inch, and ceased when the boil- 

 ing sheet was reduced, the escape of steam without that pecu- 

 liar sound, even under a pressure of 32 inches, causing the 

 separated gold leaves to collapse. 



The temperature of the glass bell seemed to be of little 

 consequence, as the experiment succeeded on the first trial 

 when the glass was quite cold, as well as when the bell had 



