V 
CONTENTS. 
X. A disquisition on the Stability of Ships. By George 
Atwood, Esq. F. R. S. p. 201 
XI. Quelques Remarques d’Opfique, principal ement relatives a 
la Refiexibilite des Rayons de la Lumiere. Par P. Prevost, 
Professeur de Philosophic a Geneve , de I’Academie de Berlin, 
de la Societe des Curieux de la Nature, et de la Societe Royale 
d’ Edimbourg. Communicated by Sir Charles Blagden, Knt. 
F. R. S. p. 31 1 
XII. An Account of the Orifice in the Retina of the human Eye, 
discovered by Professor Soemmering. To which are added, 
Proofs of this Appearance being extended to the Eyes of other 
Animals. By Everard Home, Esq. F. R. S. p. 332 
/XIII. A Description of a very unusual Formation of the human 
Heart. By Mr. James Wilson, Surgeon. Communicated by 
Matthew Baillie, M. D. F. R. S. p. 346 
XIV. Account of a singular Instance of atmospherical Refraction. 
In a Letter from William Latham, Esq. F. R. S. and A. S. to 
the Rev. Henry Whitfeld, D. D. F. R. S. and A. S. p. 357 
XV. Account of a Tumour found in the Substance of the human 
Placenta. By John Clarke, M. D. Communicated by the 
Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S. p. 361 
XVI. On the Roots of Equations. By James Wood, B.D. Fellozv 
of St. John s College, Cambridge. Communicated by the Rev. 
Nevil Maskelyne, D . D. F. R. S. and Astronomer Royal. 
p. 369 
