Researches in (he Theory and Calculus of Operations. 279 



is to arouse reaction by the formation of a series of small 

 condensed portions of the substance, which determine the 

 length of the radii of oscillation, or of the atoms thus called 

 into separate existence : by the continuance and increase 

 of this pressure, these newly formed atoms are crowded 

 closer together in line, and a boundary of greater density 

 is formed between every two adjacent ones, which remained 

 fixed after the pressure is withdrawn ; and now determinate 

 atoms exist (polarization of atoms, the boundaries act as a 

 dielectric). In undertaking transmission in this state of the 

 line, each atom has to reverse its action from right to left, 

 to hand its burthen to the next neighbor across the border : 

 this done, the atom is instantly filled by the constantly 

 emanated force of the substance of the compressed body, 

 but in a time not greatly less than is required to fill the 

 whole length of the incompressed body, and the atom is 

 then ready to receive a fresh charge ; and as this discharge 

 filling, and recharging of atoms must take place successively 

 along the whole line, we see that the poor conductor's re- 

 putation is indemnified. 



Fixed atoms are formed by compression in this way. The 

 centre (fig. 18) of the figure AA' or BB' will be the centre 

 of the longitudinal compression, and is the centre of the 

 longitudinal emanation, which, however, does not interfere 

 with the transversal emanation from the axis in every atomic 

 division throughout the cylinder. The end A' being fixed, 

 by applying compression at the end A, the atoms begin to 

 develop at both ends of the cylinder, ed meets cd at the end 

 of the first instant ; dc meets be at the end of the second 

 instant, and the compressed atom ed in BB' is filled by 

 axial emanation during the same instant; in its turn, meets 

 ab at the end of the third instant, while dc is filled by ema- 

 nation, and so on till the centre O is reached from both 

 ends B and B' of the cylinder, the boundaries being at a, 

 b, c, etc. 



