CONTENTS. 
XXXVII. A Letter from Father d’Incarville, of 
the Society fl/Jefus, at Peking in China, to the 
late Cromwell Mortimer, M. D. R. S. Seer. p. 273. 
XXXVIII. A Letter from Mr. T. Melvil to the Rev. 
James Bradley, D. D. F. R. S. With a Difcourfe 
concerning the Caufe of the different Refrangibi- 
Jiry of the Rays of Light. p. 261. 
XXXIX. 'The Cafe of the Operation for the Empye- 
ma, fnc cefsf ully performed by Mr. jofeph Warner, 
F. R. S. and Surgeon to GuyT Hofpital. p. 270. 
XL. Extract of a Letter from Mr. James Dodfon 
to Mr* William Mountaine, F. R . S. p. 273. 
XLI. A Letter from John Lining, M. D. of Charles- 
Town, South-Carolina, to the Rev. Tho. Birch, 
D. D. Seer. R. S. concerning the Quantity of 
Rain fallen there from January 1738, ^Decem- 
ber 175-2. p. 284. 
XLII. A Letter from Mr. Emanuel Mendez da 
Cofta, F. R. S. to the Rev. Tho. Birch, D. D. 
Seer. R. S. concerning the Foil’ll, found at Dudley 
in Staffordfhire, and defer ibed in Phil. Tranfact. 
N. 496. p.286. 
XLIII. Letters relating to a Theorem of Mr. Euler, 
of the Royal Academy ^Sciences at Berlin, and 
F. R. S. for cor re Fling the Aberrations in the Ob- 
jed-Glah'es ^/'refrading Telefcopes. p. 287. 
XL1V. A remarkable Cafe of Fragility, Flexibility, 
and Dillolution, of the Bones * communicated by 
John Pringle, M. D. F. R. S. p. 297. 
XLV. Agronomical Observations, made in Surry - 
llreet, London, by J. Bevis, M. D. and J. Short, 
A.M. F.R-S. p. 301. 
XLVL A Letter from Mr. John Ellis to Mr. Peter 
Collinlon, 
