of Edinburgh^ Session 1862-63. 
119 
It is interesting to observe that a particular value of <r^ in this 
case is 
cr^=-l<lSaUp-^, 
as may easily be proved by substitution. 
Again, if 
S8p^^-S^, 
we have evidently 
Sap 
Tp3' 
cr= <1 
Now, as is the potential of a small magnet a, at the origin, on 
a particle of free magnetism at p, cr is the resultant magnetic force 
— and represents also a possible distortion of the elastic solid by 
external forces, since < cr- = < = 0, and thus (16y and (17) are 
both satisfied. 
The following Gentlemen were duly elected Fellows of 
the Society : — 
The Hon. Geoege Waldegeave Leslie. 
The Hon. Chaeles Baillie (Lord Jeeviswoode). 
James Sandeeson, Esq., Surgeon-Major Madras Medical Staff. 
The following Donations to the Library were announced:— 
Abhandlungen herausgegeben von der Senckenbergischen natur- 
forschenden Gesellschaft. Yierten Bandes zweite Lieferung. 
4to. — From the Society. 
Proceedings of the Geological Society of London. Nos. 95 and 96. 
8 VO. — From the Society. 
Les Grandes Usines de France. 4 Parts. 8vo. 
Natural History of New York. VoL III., Part 6, on Palaeonto- 
logy. 2 Yols. 4to. — From the American Government. 
Natural History of New York. Part 5, on Agriculture. 4to. — 
From the same. 
TTTTTOKpdrous Kat aXkijiV iarpoiv TraXatcov Xuif/ava. Edidit Franciscus 
Zacharias Ermerins. Yolumen Secundum. Trajecti ad 
Khenum, 1862. 4to. — From the Dutch Government. 
Yerslagen en Mededeelingen der Koninklijke Akademie van 
