Mr. R. Phillips on Eledricittf and Steam. 491 



gold-leaf is then powerfully attracted by, and drawn into con- 

 tact with the vibrating plate. I suppose this observation is 

 new, and very significant with regard to theories of attraction 

 and repulsion, although I have not pursued it further. 



38. As this electrometer was very sensitive, I more gene- 

 rally employed another, with two short gold leaves, and which 

 was very far from being a sensitive instrument. This instru- 

 ment was always employed except where I have mentioned 

 that the single-leaf electrometer was used. 



39. Throughout these experiments the steam was at 40 lbs. 

 on the inch, and was supplied from the same little boiler and 

 discharged horizontally as before (7.). 



40. The Armstrong's condenser was removed, and the brass 

 jet (9.) was united to the cock of the boiler by two short brass 

 connecting pieces. This brass jet originally belonged to an 

 oxyhydrogen blowpipe, and its shape was slender and conical, 

 and the small hole at the end of the jet from which the steam 

 escaped was \ inch long, the remaining portion of the bore 

 was ^ inch diameter. The boiler communicated with the 

 electrometer by means of a wire. When the cock was opened, 

 the boiler became negative. 



41. In order to collect the electricity of the steam, I used a 

 piece of wire-gauze, insulated and supported on a stand, and 

 which by means of a wire could be made to impart its elec- 

 tricity to the electrometer; the extent of one side of the piece 

 of wire-gauze was about 2*5 square inches. The electricity 

 of the steam was thus found to be positive. 



42. A straight glass tube about 3 feet long and '4 inch dia- 

 meter, was placed horizontally with the brass jet projecting 

 into it to the extent of the jth of an inch; the tube was also 

 supported so that an annular space existed between the end 

 of the jet and the tube. In order to ascertain the electrical 

 state of the inside of this, or any other tube, a few inches of 

 its length were covered externally with a piece of tin-foil and 

 bound on with wire, the other end of which could be taken 

 to the electrometer. 



43. When the steam was turned on, the tube and boiler 

 both became negative. A connexion existed between the tube 

 and the boiler; for when the leaves of the electrometer were 

 divergent, touching the boiler made them collapse. Some- 

 times the first action of the steam was to make the leaves di- 

 verge to a small extent, then to make them approximate a 

 little, and then to cause them to open much more with a ne- 

 gative charge; but when the connexion between the tube and 

 the electrometer was broken before the approximation took 

 place, the instrument was found to be positively charged. 



