258 Mr. Knox on the Direction and Mode of 



EXPEKIMENTS. 



The bent glass tube which I employed In my former experiments having been 

 filled alternately with muriatic acid, hydriodic acid, sulphate of copper, and mu- 

 riate of ammonia, and the circuit being completed by a current from a sustaining 

 battery of one pair of elements, the same law was found to subsist as when water and 

 phosphorus were employed, i. e. that the current passed through their substance 

 and not along their surface. The same likewise took place when the tube was 

 filled with fused chloride of tin, which conducts by electrolysis, and fused periodide 

 of mercury, which conducts by conduction. 



To determine whether this law with regard to liquids which convey a gal- 

 vanic current subsists when non-conducting fluids are employed, I filled the 

 tube alternately with alcohol, naphtha, oil, fused lard, bees' wax, and resin, and 

 having connected one of the insulated wires with the ground, I connected the 

 other with an insulated brass ball, fixed at the distance of four-tenths of an inch 

 from the prime conductor, of a nine inch electrical machine. 



ALCOHOL OR NAPHTHA. 



When the platinum wires were immersed in the legs of the bent tube until 

 their extremities were placed at the distance of five inches, ten sparks passed in 

 one revolution of the plate ; when at two feet distance, eight sparks ; when at four 

 feet distance, six sparks. 



OIL. 



At the distance of five inches, seven sparks passed in one revolution of the 

 plate; at the distance of two feet, four sparks passed ; and at the distance of four 

 feet, two sparks passed in one revolution. 



FUSED LARD. 



At the distance of five inches, two sparks passed in one revolution of the 

 plate ; at the distance of two feet, one spark in one revolution ; at the distance of 

 four feet, one spark in three revolutions. 



bees' wax. 

 At the distance of five inches, one spark passed in one revolution of the 

 plate ; at the distance of two feet, one spark in one revolution and a half; at the 

 distance of four feet, one spark in two revolutions. 



