206 
and the pressure of this mixture ona unit of surface will be, as 
before, & x number of molecules in the unit of volume. Hence, 
denoting this pressure by P, we shall have 
n+on +n" 
sie v 2 v 
and therefore 
Malt 
VP=vp+vp'+v'p’, 
the same expression as that deduced under the supposition of 
non-mutual action. 
vu 
Mr. Haughton mentioned that Mr. Patton, the author of 
the last paper, had forwarded to him a sum of money to pro- 
vide a European collection of rocks and fossils, for the purpose 
of promoting the advancement of science among the Hindoos. 
The Secretary exhibited an ancient circular piece of bronze, 
containing figures on both sides, the property of Mr. Quinn, 
of Belfast. 
The Rey. J. H.'Todd, D.D., Secretary, exhibited an ancient 
ecclesiastical bell, and read a letter from John Bell, Esq., of 
Dungannon, relative to it. The bell is the property of Mr. 
M‘Clelland, of Dungannon, who has kindly permitted it to 
be exhibited to the Academy. It is said to have been found 
in the cabin of a poor fisherman, at Fahan, six miles north-west 
of Derry, on Lough Swilly, in Innishowen, and was recently 
purchased by Mr. M‘Clelland. Fahan, or Fahan-mura, was 
a monastery, dedieated to St. Murus or Muranus, and founded 
by St. Columba (Colgan, Trias Thaum., p. 495 and 510). St. 
Murus, second Abbot of this house, flourished in the begin- 
ning of the seventh century, and from the fame of his sanctity 
has since been reputed its patron. Of the relics preserved in 
this monastery, Colgan mentions a MS. life of St. Columba, 
in Irish metre, written by St. Murus himself; a chronicle, also 
