iv CONTENTS. 



Remarks on the Origin o///?^ Vegetable Fixed 

 Alkali, with /ome collateral Obsekv^tiovis on 

 Nitre. By M. Wall, M. D. PraleSfor in Che- 

 mijiry in the Univerfity of Oxford. Communicated 

 in a Letter to Br. Percivd - Page 67. 



Some Account of the Life and Writings of the 

 /fl^e Professor Gregory, M. D. F.R.S. By 

 James Johnstone, M. D. et Soc. Reg. Medic. 

 Edinb. Sccius. Communicated by Dr. Barnes 



P. 80. 



Remarks on theK-tiiowLZHGZ of the Ancients rf- 

 Jpe^ingGhASS. By Dr. pALCOiiER of Bath P.95. 



On the different Quantities of Rain which 

 fall «/ different Heights over thefame Spot 

 OF GaouNDj with a Lj^ttek from Benjamin 

 Franklin, LL. D. jBy Thomas Percival, 

 M.D. ^c-. - - P. 122. 



Speculations on thevEKCi.PTivz Power c/Vegeta- 

 BLEs. Sj'Thomas Percival, M.D. &'c. p. 130, 



^n Experimental Inquiry into the Cause of the 

 Permanent Colours of Opake Bodies. By 

 Edward Hussey Delaval, F. R. S. of the 

 Royal Societies <?/" Upsal ^w-^ Gottingen, 

 c//j^i? Institute <?/ Bologna, ^c. Communi- 

 cated by Mr. Charles Taylor - P. 147. 



Experiments and Observations on Ferments, 

 a n d F E R M E N T A t I o N J by which a Mode of exciting 

 Fermentation in Malt Liquors, without the Aid 

 of Ye AST i is pointed out ; with an Attempt 'i?(? 



forn^ 



