IV 
CONTENTS 
XIV. Experiments on Human Calculi. In a Letter from Mr. 
Timothy Lane, F. R. S. to William Pitcairn, M. D. 
F. R- S. P- 22 3 
XV. Chernies Lacca. By William Roxburgh, M. D. of 
Samulcotta. Communicated by Patrick Ruflell, M. D. F. R. S. 
p. 229 
XVI. The Longitudes of Dunkirk and Paris from Greenwich, 
deduced from the Triangular Meafurement in 1787, 1788, 
fuppofing the Earth to be an Ellipfoid. By Mr. Ifaac Dalby ; 
communicated by Charles Blagden, M. D. Sec. R. S. p. 236 
XVII. On the Method of determining , from the real Probabilities 
of Life , the Values of contingent Reverfions in which Three 
Lives are involved in the Survivorfhip. By Mr. William 
Morgan, F. R. S. ■ P* 2 4 ^ 
XVIII. AbJlraSl of a Regijler of the Barometer , Thermometer , 
and Rain, at Lyndon in Rutland ; by Thomas Barker, Efq . ; 
w ith the Rain in Hamplhire and Surrey; for the Tear 1790. 
Communicated by Thomas White, Efq. F. R. S. p. 278 
XIX. Defcription of a fmple Micrometer for meafuring- fmall 
Angles with the Telefcope. By Mr. Tiberius Cavallo, 
F. R.S. P* 283 
XXI. Experiments and Obfervations to invefigate the Compofition 
of James’s Powder. By George Pearfon, M. D. F. R. S. ; 
communicated by Sir Jofeph Banks, Bart. P . R. S. P*M 7 
' XXII. An Account of fome chemical Experiments on Tabafheer. 
By James Louis Macie, Efq. F. R. S. P- 3 68 
XXII I. A Second Paper on Hygrometry. By J. A. De Luc, 
Efq. F. R. S. P’ 3 8 9 
