422 
was easily reproduced, even when the extremities of the float rested 
in contact with those of the polar tubes before the circuit was com- 
pleted. It is obvious that here no thermo-electric effects can be 
produced in the mercury, and I have satisfied myself that the motion 
commences before the passage of the current can have sensibly heated 
the fluid in the tubes. 
The other class of objections to Ampere’s conclusion from this 
experiment, depending on the spreading of the current in the mer- 
cury of the troughs, is of course not met by this modification. I 
have made several experiments with a view to obviate this also, 
but my time has been so much occupied that I have not been able 
as yet to put them in a form suitable for communication to this 
Society. 
The following Gentleman was admitted as a Fellow : — 
James Lorimer, Advocate. 
The following Donations to the Library were announced : — 
On the Causes of Death in the Scottish Widows’ Fund Life As- 
surance Society, from January 1853 to January 1860. By James 
Begbie, M.D., F.B.S.E . — From the Author. 
Proceedings of the Boyal Horticultural Society, Nos. VI. XVI., 
1860 ; XXI., 1861 . — From the Society. 
Monthly Notices of Astronomical Society, Vol. XXI., No. 3.- — 
From the Society. 
Transactions of the Linnean Society, Vol. XXII., Part 4 ; 
XXIII., Part 1, 4to .- — From the Society. 
