22 



HISTORY of the SOCIETT. 



1784. had the misfortune to lofe. Having found it to be the gene- 

 ral opinion of thofe members with whom he had an opportu- 

 nity of converfing upon the fubjecl, that fuch biographical ac- 

 counts would form a proper appendix to the hiftorical part of 

 thefe Tranfa&ions, he had prepared this brief detail, preceded 

 by fome general obfervations, as an introduction to future ac- 

 counts of the fame kind. The plan was approved of by the 

 Society ; and the Reader will find this Effay followed by others 

 of a fimilar nature, forming an appendix to the hiftorical part 

 of this volume. 



April it. 

 Mr Greenfield 

 on negative 

 quantities in 

 algebra. 



Dr Button's 

 theory of rain. 



Earl of Dundo- 

 nald on fea-falt. 



Pbyf. Cl. THE Reverend Mr WILLIAM GREENFIELD read a 

 paper on the ufe of Negative Quantities, in the Solution of Pro- 

 blems by Algebraic Equations ; which is publifhed in this vo- 

 lume. [No .IV. Pbyf. Cl.] 



Dr HUTTON read the continuation of his paper on the Theo- 

 ry of Rain, publiftied in this volume. [No. II. Pbyf. Cl.] 



Dr WALKER read a, letter from the Earl of DUNDONALD, 

 giving an account of fome further experiments on the purifica- 

 tion of fea-falt, which his Lordihip communicated in compliance 

 with the requeft of the Society, at their meeting in February. 

 The fubftance of the Earl's obfervations will beft appear from 

 the following table. Each portion of fait was purified by four 

 warnings, according to the method formerly defcribed. 



T A B L E. 



