to the Air by a Steam Jet 129 
| 
other volatile bodies, but the charge was by no means invariable 
and generally changed to positive after the material had been 
volatilised. 
TABLE I. 
Liquid in boiler parse Nn Remarks 
Wiscilled water 6. 4.....2<c..c8e ences Positive Charge strong 
BOMTLON Of Salt Wii. ...cecc0tee one. 5 5 4 
s Caustic Soda, .2:....-- . 3 
55 potassium nitrate... [9 % 
53 magnesium sulphate s 3 wm 
‘ ammonium carbonate Negative After boiling for some 
time became positive 
Bs benzoic acid ......... ; Positive 
*s VINCCAN seaeceersccses Negative Charge weak 
a hydrochloric acid ... * Fairly strong 
rs hydriodie acid ...... a 5 “5 
Distilled water with a small 5 Very strong at first 
piece of phosphorus............ 
Iodine in potassium iodide ...... % Charge weak positive 
after a short time 
It was not easy to prevent a charge being given to theair. If 
there was any visible condensation and the pressure was above one 
and a half atmospheres a charge was invariably obtained. Passing 
the steam through a red-hot tube had no effect in reducing the 
charge, but placing a large bunsen burner directly in front of the 
jet caused most of the charge to disappear if at the same time 
visible condensation ceased. 
If a jet of steam gives a positive charge to the air it is obvious 
that a negative charge must be somewhere and one naturally 
looks for this on the boiler. This negative charge is readily 
detected by heating the boiler until a good pressure is obtained, 
and then placing it on an ebonite support. On connecting it to an 
electroscope the presence of the negative charge is at once shown. 
As is well known, an insulated conductor held in a current of 
high pressure steam, acquires a positive charge, but under some 
circumstances a negative one can be obtained, and some casual 
observations appeared to indicate that the nature of the charge 
depended upon the position of the electrode. It seemed of interest 
to investigate this point and it was then found that a positive or 
negative charge could be obtained as desired, by suitably placing 
the exploring electrode, An arrangement was therefore made by 
which an exploring electrode could be moved about in the steam and 
the position noted where positive or negative charges were found. 
