24 
zontal ordinates of any point in the surface, with origin a point 
equally distant from the plates, and the axis of y perpendicular 
to them in the level of the outside liquid. For tubes of any 
diameter held vertically in a liquid a differential equation was 
found and a relation between the ordinates expressed in an 
infinite series, but an equation in finite terms was not found. 
The equation for parallel plates is similar to that for the cate- 
nary curve for a uniform chain, but differing from it in having 
the constants different from each other. 
The first terms of the expansions in series of these two 
cases give the results which were before found by approximate 
methods. 
In the discussion which followed, Proressor CHALLIS made 
some remarks upon the difficulty of the subject which Mr 
Potter had been investigating, but reserved his approval of the 
method followed until he could give the argument a fuller 
consideration. Pkroressor STOKEs objected to the method pur- 
sued, and was unable to agree with the results obtained. 
May 7, 1866. 
PROFESSOR STOKES (Senior Member of the Council present) 
in the Chair. 
On the Root of any Function; and on Neutral Series, 
No. II. By Prof. De Moreay. 
THE author divides algebraical thought into quantitive and 
structural. A quantitive proposition is seen in ‘A value of x 
can be found, so that @x =a’: a structural proposition in ‘If 
y =x, there exists a form, @', such that c=¢"y.’ These 
