a Nero Dj/namico- Chemical Principle. 1 7 7 



the remaining force in continuing the motion towards A B, 

 and bringing the other extremity b likewise in contact with 

 it, thus inducing a contrary rota- 

 tory motion, which by encoun- V 

 tering and balancing the former ,\ 



will concentrate the whole force 

 in the centre of gravity, and thus 

 cause the line to shoot forwards ,\--'' 



from AB in radiating lines wx; 

 nearly the whole momentum be- 

 ing now exerted in a rectilineal 

 direction. Thus the lines after 

 collision with the plane AB will 

 convey a newly acquired impulse e 



radiating from every point of its 



surface, and the rectilineal force thus generated will be com- 

 municated from one part of the medium to another. For we 

 may suppose the fluid surrounding the plane to be divided 

 into concentric films, and the primary rectilineal impulse oc- 

 casioned by the introduction of the plane to be communicated 

 from the first to the second, from the second to the third, 

 and outwards successively. After the mutual reflection which 

 takes place between the first and second, the former will 

 have given away a portion of its rectilineal force, whilst the 

 supplementary portion is converted into a rotatory motion. 

 The same interchange will take place between the second and 

 third films, whilst at every collision an absolute loss of recti- 

 lineal momentum will be incurred, which will continually re- 

 place the vibratory reflections of the first film on the rigid 

 plane. The radiating influence will be thus conveyed through 

 boundless space, its intensity diminishing in a ratio of the 

 distance. The balance of forces which before the introduc- 

 tion of the plane AB had preserved the homo- 

 geneity of the medium will be now destroyed, 

 and the density of its relative parts will be pro- 

 portional to the intensity of the rectilineal ve- 

 locity of the component particles. Thus the 

 difference between the density of the fluid at 

 any point surrounding the plane, and of the 

 same before the introduction of the plane, will 

 decrease in a ratio expressed by some function 

 of the distance of that point from the centre of 

 impulsion. This ratio if //wmr/j/ developed will 

 be represented by a curve /-Z originating at a 

 finite distance a/c from the axis ab expressing the density of 

 the medium at the surface of the plane at a, and gradually 

 N. S. Vol. 10, No. 57. Sept. 1831. 2 A approachmg 



