Influence of Proximity of Substances upon Voltaic Action. 441 



9400 oooooo P ar ^ °f ^bat obtained with the six vertical tubes, 

 and quite unrecognizable • by means of a galvanometer, 

 especially in the presence of a variable amount of unbalanced 

 voltaic action which cannot be entirely excluded. 



Numerical calculations, however, frequently lead to error 

 unless they are sufficiently supported by facts ; notwithstand- 

 ing that the excessively feeble action of gravity, and the 

 relatively large amount of purely voltaic action, rendered it 

 highly improbable that any perceptible electric effect would 

 be produced, on a number of occasions between the years 

 1849 and 1894, I devised and constructed various apparatus, 

 and made numerous series of experiments and observations 

 with them, in the hope of rendering such an effect perceptible. 

 One was a vertical cylinder of guttapercha six feet high and 

 six inches diameter, fitted with terminal electrodes attached 

 to a galvanometer, filled with an electrolyte, and capable of 

 revolving on a horizontal axis ; a second was a massive wooden 

 .frame, provided with a high resistance-coil of very fine 

 insulated copper wire leading to a galvanometer, and capable 

 of being revolved upon a horizontal axis at a speed of more 

 than 4000 revolutions per minute ; a tbird consisted of two 

 very compact and well insulated voltaic batteries of one 

 hundred cells each, connected in opposition with a high 

 resistance galvanometer, and separately attached to the two 

 ends of a cord passing over a pulley fixed to a ceiling, so 

 that one might be raised whilst the other was lowered through 

 a distance of about twenty-two feet ; and several others which 

 need not be mentioned, The first really positive results were 

 obtained in June 1894 ; and I will briefly describe some of 

 the experiments made with three of the successful apparatus, 

 substantially in the same chronological order in which they 

 were made ; the most perfect ones are those of the most 

 recent date. 



Experiments with Apparatus No. 1. 



In this section of experiments the apparatus consisted 

 essentially of a massive influencing or " attracting" body; 

 a series of fourteen tubes of electrolyte similar to those already 

 mentioned, and a Thomson reflecting galvanometer having a 

 resistance of 3040 ohms. The influencing mass, already 

 mentioned, was composed of 72 pigs of lead, having a total 

 weight of 8271 lb., or about 74 cwt., supported upon a solid 

 brick floor and free from any perceptible vibration. The 

 glass tubes containing the liquid were each about 75 inches 

 long and J inch internal diameter, fixed upon a perfectly 

 horizontal and stout board which was capable of smooth 



