Chemical Force in the Spectrum. 97 
them, from associated particles. No vibrations therefore are 
originated, no heat is produced, there is no lateral conduction. 
pred. Up to a certain point the dislocation taking place may 
and removal of such a sheet. But a certain point of tempera- 
ture or exposure gained, the paper scorches, that is, undergoes 
chemical change, and then there is no restoration, no recovery 
of its original condition. Hence it may be said of such a sheet 
of paper that it exhibits two phases, in the first of which a re- 
turn to the original condition is possible, in the second such a 
return is impossible, because of the supervening of the chem- 
leal change. 
N investigation of the effects produced by a ray presents 
then, these two separate and distinct phases, the physical and 
the chemical. 
General Conclusions. 
The facts presented in the former and the present memoir 
Suggest the following conclusions: 
Ist. That the concentration of heat heretofore observed in the 
&ss refrangible portion of the prismatic spectrum, arises from 
the special action of the prism, and would not be perceived in a 
diffraction m. 
2d. From the long observed and unquestionable fact, that 
there is in the prismatic spectrum a gradual diminution in the 
Jeat-measures from a maximum below the red to a minimum 
m the violet, coupled with the fact now presented by me, that 
e heat of the upper half of the spectrum is equal to that of 
the lower half, it follows that the true distribution of heat 
throughout. the spaces of the spectrum is equal. In conse- 
quence of the equal velocity of ether-waves, they will on com- 
Plete extinction by a receiving surface generate equal quanti- 
tles of heat, no matter what their length may be. Provided, 
Am. Jour, se yeni, Vou. V, No. 26.—Fes., 1873. 
