VI 
CONTENTS. 
VI. A Table of the mean Heat of every Month for Ten Tears in 
London, from 1763 to 1772 inclufively. By William 
Heberden, M. D. F. R. S. and A. S. p. 66 
VII. On Centripetal Forces. By Edward Wariwg, M. D. 
F. R. S. Prof for of Mathematics at Cambridge. p. 67 
VIII. Experiments on local Heat . In a Letter from James Six, 
Ejq. to the Rev. Francis Wolhfton, LL.B. F. R. S. p. 103 
IX. Obfervations on the Manner in which Glafs is charged with 
the el e Uric Fluid , and dif charged. . By Edward Whitaker 
Gray, M. D. F. R . S. p. 121 
X. Experiments on the cooling of Water below its freezing 
Point. By. Charles Biagden, M. D. Sec. R. S.-and F. A. S. 
p. 125 
XI. Experiments and Obfervations relating to the Principle of 
Acidity, the Compofition of Water , and Phlogifion. By 
jofeph Prieflley, LL.D. F. R. S. p. 147 
XII. Some Obfervations on the Irritability of Vegetables. By 
James Edward Smith, M. D. F. R. S. p. 158 
XIII. An Account of Experiments made by Mr. John M c Nab, 
at Albany Fort, Hudfon’s Bay, relative to the Freezing oj 
Nitrous and Vitriolic Acids. By Henry Cavendilh, Efq. 
F . R» S. and A.S . p. 166 
APPENDIX. 
TTranflation of Don Michael Rubin de Celis’s Letter to the 
Royal Society , relative to a Mafs of native Iron , found in 
South- America. p. 183 
A Meteorological Journal liept at the Apartments of the Royal 
Society, by Order of the P ref dent and Council • p. 19 1 
PHILO- 
