Proceedings of Scientific Societies. 383 



water, in the boiler; but in tliis case the steam was always accompanied 

 by a spray of water, and the experiments failed. They also failed when 

 the steam was of a low temperature, as it was then condensed immedi- 

 ately upon leaving the boiler, so as to form a cloud of vesicular vapor. 

 In both these cases, the electricity, if evolved at all, would be led back to 

 the boiler — the spray and the vesicular vapor being, as is well known, 

 electrical conductors. 



When, on the other hand, high steam was drawn off from a stop-cock 

 far removed from the water in the boiler, it was observed to issue, for 

 some distance, in the form of a transparent gaseous vapor, and, in this 

 ca.se, any insulated body on which it was condensed was always found to 

 be charged with electricity. Thus, if the experimenter stood on an in- 

 sulating stool, or even on a box or ladder of dry wood, and held an iron 

 ladle, or any other conductor, in the issuing steam, the conductor and the 

 operator became so fully charged with electricity, that thick sparks of a 

 half, three-quarters, and in some instances a whole inch in length, were 

 drawn off; the Leyden jar charged ; the shock given to several persons 

 holding hands, &c. The electricity thus produced was found to be al- 

 ways positive. 



Dr. P. said, that one of the most important conclusions to which the ex- 

 periments had led, was, that true gaseous steam is a non-conductor of 

 electricity. If it had not been so, the apparatus would not have been in- 

 sulated, and the electricity excited would have been carried back to the 

 metallic boiler, and thence to the earth. 



Dr. P. thought it most probable that the electricity, in these experi- 

 ments, was evolved by the condensation of the steam — the phenomenon 

 being analogous to the evolution of latent heat by the same condensationo 

 He remarked, thai as the steam within the boiler was surrounded by con= 

 ductors, it could not be supposed to contain free electricity, and that on 

 leaving the boiler, the only sources to which the electricity could be as- 

 cribed, seemed to be the condensation of the steam, the oxidation of the 

 iron against which it impinges, or the friction of the steam against the air 

 as it rushes through it. 



To show that oxidation was not the source of the electricity, the exper- 

 imenters caused the steam to strike upon a large bar of fine gold, (400 oz. 

 in weight,) and the generation of electricity was as abundant as when 

 they employed an oxidizable metal. The electricity was also evolved by 

 the insulated operator simply holding his hand in the steam as it issued ; 

 in which case the steam was condensed upon the hand, and the whole 

 person became charged. Dr. P. stated, that this was, in fact, the experi- 

 ment accidentally made near New Castle, in England, and which has at- 

 tracted so much attention. 



To show that the electricity was not caused by the rushing of the 

 vapor through the air, Dr. P. said that an apparatus was made, consisting 



