﻿416 Dr. Guyot on the Forms and Forces of Matter. 



attraction of other atoms, then it should also be true that a so- 

 norous body acting on the air, on water, or other elastic medium 

 will rarefy the fluid which envelopes it and attract to its sur- 

 face bodies suspended or floating within the sphere of its acti- 

 vity. This question was neither proposed nor solved when I 

 published my Elements de Physique Generate. It was proposed 

 and solved in 1832 and 1835, at the date of publication of my 

 work on the movements of air and the pressure of moving air. 



In 1832, during more than six months of varied and conti- 

 nuous experiments, the phenomenon refused to disclose itself 

 to me ; but I was convinced of its existence, and I should never 

 have given up my search for it but with life. I had vainly tried 

 the action of the tuning-fork upon all sorts of substances,when 

 a pharmacist drew my attention to the pith of the Sunflower 

 (' ( grand soleil") as a most light and bulky substance, and got me 

 some of it. I made a little disk of this substance, which was 

 attracted by the fork. It was attracted in all directions, and by 

 all the faces of the vibrating instrument. It was even attracted 

 by a needle connected with and forming a continuation of one of 

 the prongs of the fork. Once master of the fact at first nearly 

 imperceptible, it was not long before I reproduced it with ease and 

 made it as palpable as magnetic attraction. I soon found that 

 in order to get a proper action it was sufficient to expose to the 

 vibrating surfaces a proportionally large surface in the pendulum 

 subject to the influence. Rods, cups, cords, and plates in vi- 

 bration attract, direct, or repel with the same appearances as 

 electrified bodies. They act at a distance, and propagate their 

 action through space to all surrounding bodies like electricity, 

 heat, and light. ^ 



I take a tuning-fork and put it in vibration in the ordinary 

 manner, I bring it near to a disk of vegetable paper hung from 

 two silk threads without torsion. The disk is then seen to ap- 

 proach the surface from a distance of one or two centimetres, 

 to touch the surface and to vibrate with it, and to detach itself 

 as soon as by contact the vibration of the instrument is stopped. 

 If the vibrating surface be increased by fastening a little card 

 on to the external face of one of the prongs of the fork, the 

 effects are produced from a greater distance, the pendulum is 

 moved and attracted by the card, and remains in contact with 

 it for a comparatively long time ; and the distance of the attrac- 

 tions is proportional to the squares of the attracting and attracted 

 surfaces*. 



On passing the bow across the edge of a cup or of a bell 

 of metal or glass, the same phenomena of attraction are shown 



* It is to be regretted that this important point is stated with some am- 

 biguity. — F. G. 



