Chase.] ^^^ [Jan. 21, 



The Holston uplift is reached at the summit between Wolf creek, North 

 Branch, and the " rich valley " of Abraham's creek. There, one comes to 

 tlie limestones of the Knox group, in contact with the highest rocks of the 

 mountain limestone group, and two miles further along the railroad 

 line the cherty beds of the Knox group are exposed. These are shown 

 very near to Walker's mountain at a cross-road, where the soil is very fer- 

 ruginous. The limestones of the overlying group are shown at but a little 

 way from the gap by which the railroad passes through Walker's mountain. 



A well-marked f\iult was crossed just behind Walker's mountain at some- 

 what more than four miles from Bristol, where the pyritous calcareous 

 sandstones of the Knox group are shown in the gap through that ridge. 

 The dip is abrupt at the head of the gap and increases to the mouth, where 

 it becomes nearly 50 degrees, and the shaly layers are badly twisted. Ex- 

 posures are very obscure between this localit}' and Bristol, where the line 

 of section terminated ; but the limestones of the Knox group are shown 

 here and there, and the cherty beds of that group pass very near to Bristol. 



Photodynamic Notes. By Pliny Earle Chase, LL.B. 



{Read iefore the American Philosophical Society, Ja.nuary 21, 1881.) 



1. Chemical Synchronism. 



Maxwell* appears to have originated the theory, which is now generally 

 accepted, of the equality of meanwis viva in the molecular movements of dif- 

 ferent gases, at equal temperatures. In 1863, 1 began to investigate some of 

 the consequences ot the theory, and the many evidences which I have ad- 

 duced, of cyclical and harmonic vibrations in atmospheric and sethereal 

 media,f have more than justified my belief of its importance. 



All harmonies in elastic media necessarily involve some form of syn- 

 chronism, and the progress of chemical physics may be helped by a knowl- 

 edge of the general kinetic laws upon which such synchronism depends. 

 If we designate velocity by v; density, by d; tiuie of rotation, by t; modu- 

 lus, hy h; absolute temperature, by T; and the acceleration of a central 

 force, by/, Maxwell's theory may be represented by the equation y^ d = 



ft — 



Ti T. In the fundamental equations of central force -y = -:3^ = F \/fr; 



h = -y. When the efficient or fundamental velocity is constant, as in spatial 



Photodynamics, foc—oc — ex — cc — ; t <x h oc \' — cc roc— ; h oc r <x 

 t h f r ^ f f 



— oc ff oc t. Whenever we have occasion to consider derivative or second- 

 / 



*P. Mag.,1860r41, 19, 19. 



tProc. Amer. Phil. Soc, ix, 284-7; xvii, 109-12, 294-307; xvili, 224-32; xix, 4-9 

 20-5; etal. 



