TT 



8abc 



1879.] fo7- a rectangular parallelepiped. 293 



dt 



iaA 



(. / x-x, _-^-%N ^ / a' + .r, -'I 



e 46^" ) + V, ['TT''—^ , e 462^ 



In order that there should be no flux across the faces, a sink 

 of discharge 47r must be placed at some point oc^y^^z^ in the interior 

 and then the velocity-function of the motion is ^j— ^2' where c^)^ is 

 derived from ^^ by writing x^y„z^ for x^y^z^. 



Thus for a source and sink at the opposite corners (0, 0, 0) 

 and (a, h, c) 



*=^c/:<s--')^.(i--*')<s- ^--') 



dt 



By certain distributions of sources and sinks along the edges 

 and faces of the parallelepiped, it will be possible to construct the 

 solution of the problem of the permanent temperature of the in- 

 terior when the faces are maintained at certain temperatures ; also 

 by a proper distribution of sources and sinks over a surface in the 

 interior it will be possible to discover the motion of the liquid 

 when set in motion by the surface and bounded by the faces. 



November 24, 187.9. 



Professor Newton, President in the Chair. 



Mr Alexander Scott, B.A., of Trinity College, was ballotted 

 for and duly elected a Fellow of the Society. 



The following communications were made to the Society : 



Mr A. Sedgwick, B.A. — A preliminary -notice on the de- 

 velopment of the kidney in its relation to the Wolffian body in 

 the chick. 



To render clear the account of the development of the kidney, 

 and to show its relation to the Wolffian body, it is necessary to 

 give a short account of the development of the latter. Anteriorly 



22 — 2 



