Proceedings of Scientific Societies. 385 



through the whole capacity of the air, is of very feeble intensity, although 

 of great quantity ; but the condensation of the vapor into a cloud affords 

 a continuous conductor, and consequently the electricity of all the parti- 

 cles of the interior, according to the well known principles of distribu- 

 tion, rushes to the surface of the cloud, and hence the great intensity of 

 the lightning. According to this hypothesis, the insulated conductor, 

 placed in the steam, would act not only as a collector, but also as a con- 

 denser of the free, but feeble electricity of the vapor. 



Prof Henry farther stated, in connection with this subject, that he had 

 been informed by several persons, that they had obtained sparks of elec- 

 tricity from a coal stove during the combustion of anthracite. A case 

 had been stated to him several years ago, which he mentioned to his 

 friend. Professor Bache, who informed him that a similar one had fallen 

 under his own notice, in which, however, Prof Bache had succeeded in 

 tracing the electricity to the silk shitt of the person who drew the spark. 

 Another case had lately been reported to him by an intelligent gentleman, 

 of a stove burning bituminous coal, on board of a steamboat on the Ohio, 

 which afforded amusement to all the passengers during the voyage, by 

 giving sparks of electricity whenever it was touched. 



In connection with tire facts that had been stated of the production of 

 electricity from steam. Prof Henry observed that he was now inclined to 

 believe that electricity may also be evolved during the combustion of coal 

 in a stove. But what, he asked, is the source of electricity in this case? 

 Is it combustion, the evaporation of the moisture, or the friction of the 

 hot air on the interior of the pipe ? 



Dr. Goddard stated, that in the case of a stove, pretty well insulated, 

 his family had amused themselves with drawing sparks half an inch or 

 three quarters of an inch long; and that similar sparks were obtained 

 from the frame of a looking-glass over an open grate, in the house of Dr. 

 Norris, of this city. 



Professor Bache remarked, that in the case referred to by Prof Henry, 

 in which sparks of electricity were obtained from a stove, he had satisfied 

 himself that these were owing to the experimenter wearing a silken 

 shirt: — an experimenter, not similarly clad, being unsuccessful. 



Dr. Hare ascribed the incredulity and the opinions which he had ex- 

 pressed, when this subject was brought before the society by Mr. Peale, 

 at the last meeting, to a misapprehension, on his part, as to the circum- 

 stances. He considered that the fact of electricity being developed in 

 the case adduced, was established. He alluded to the almost incredible 

 case of a lady, who, agreeably to evidence mentioned in Silliraan's Jour- 

 nal, Vol. xxxiii, gave off sparks of electricity. He stated also the result 

 of an experiment to discover whether electricity was given off during the 

 rapid evaporation of a saline solution. There was no evidence of excite- 

 ment. The vessel was of glass. 



