SKETCH OF ELISHA GRAY. 525 



time realize tlie full value of the invention, as his attention was mainly 

 directed to the capacity of the apparatus for transmitting musical tones 

 through an electric circuit. 



In the winter of 1874 Mr. Gray observed a singular circumstance in 

 connection with the reproduction of electrically transmitted vibrations 

 through the medium of animal tissue. On going into the bath-room 

 he found his nephew playing with a small induction coil — "taking 

 shocks," as he expressed it, for the amusement of the smaller children. 

 He had connected one end of the secondary coil to the zinc lining of 

 the bath-tub, which was dry at that time. Holding the other end of 

 the coil in his left hand he touched the lining of the tub with the right. 

 In making contact, his hand would glide along the side for a short dis- 

 tance. At these times Mr. Gray noticed a sound proceeding from under 

 his hand at the point of contact, which seemed to have the same pitch 

 and quality as that of the vibrating electrotome, which was within hear- 

 ing. Mr. Gray immediately took the electrode in his own hand, and, 

 repeating the operation, to his astonishment found that, by rubbing 

 hard and rapidly, he could make a much louder sound than the electro- 

 tome was making. He then changed the pitch of the vibration, increas- 

 ing its rapidity, and found that the pitch of the sound under his hand 

 was also changed, it still agreeing with that of the transmitted vibra- 

 tion. He then moistened his hand and continued the rubbing, but no 

 sound was produced so long as his hand remained wet ; but, as soon as 

 the parts in contact became dry, the sound reappeared. So striking 

 was the effect that, by hard rubbing with the dry hand, the noise could 

 be distinctly heard throughout the house. 



This experiment produced a profound impression upon his mind, and 

 determined him at once to take the matter up in earnest and see what 

 might be in it. He procured a violin, and, taking off the strings, sub- 

 stituted in their place a thin metal plate provided with a wire connec- 

 tion, so that he could attach it to one pole of the induction coil or bat- 

 tery, thus placing it in the same position, with reference to the body, 

 that the bath-tub was in the original experiment. By rubbing the plate 

 in the same manner as before described, the sound of the electrotome 

 was reproduced, accompanied by the peculiar quality or timbre belong- 

 ing to the violin. He noticed, however, that the characteristics of the 

 initial vibrations were faithfully preserved, and all that was needed was 

 to sift out such foreign vibrations as were excited in the receiver, owing 

 to its peculiar construction ; in which case there would remain the exact 

 character of the transmitted vibrations. 



In March, 1874, Mr. Gray undertook to secure letters patent for 

 some of his conceptions, and with that purpose in view had models 

 made, illustrating the idea of a series of transmitters, each tuned to a 

 different pitch, showing a method of receiving musical or other sounds 

 telegraphically, through the medium of animal tissue. In June, 1874, 

 he filed another case, substituting for the animal-tissue receiver an 



