TEANSACTIONS 



OF TH1C 



RO Y AL SOCIETY 



OF 



EDINBURGH. 



VOL. XXXI. 



EDINBURGH: 



PUBLISHED BY ROBERT GRANT & SON, 107 PRINCES STREET, 

 AND WILLIAMS & NORGATE, 14 HENRIETTA STREET, COVENT GARDEN, LONDON. 



MDCCCLXXXVIII. 



