4 The P R E F A C E. 
Fourthly, To give , as Opportunity offers , Abffrafls or 
Accounts of fuch Books , relating to the Ends of the Royal So- 
ciety’,* Inf it tit ion, as the Authors fhall pleafe to communicate 
them/elves ; which fhall he diflinguijked from others : or of fuch 
as an with difficulty to he procured in England, or extraordina - 
ry in their kind ; upon which there fall fometimes he added fome 
Remarks . 
To this Undertaking the Puhlijher invites and dejires all real 
'Lovers of Knowledge to contribute their Affiflance , by communi- 
cating their Obfervations, Difcoveries, or Inventions ; which 
fhall not only he faithfully and duly Publifhed, with due Acknow- 
ledgment ; hut fome Returns made them, hy Informations of what 
fhall he thought acceptable to the Gentlemen, who fhall think fit to 
entertain a Pbilofophical Correfpondence : Who are defired, in 
any Trail or Difcourfe they fhall fo communicate, to omit all Per - 
fonal Reflections; for if fuch fhould happen to be inferted, the 
Puhlijher fall take the liberty of leaving them out ; it being his 
Opinion, that Difputes on Pbilofophical Subjects, may be mana - 
ged with the utmofl Candor, RefpeCt and Friendjhip by the Dif- 
putants, wbofe only Aim ought to be the Search if Truth . 
The Gentlemen willing to encourage this Undertaking,, are de- 
fired to direlt their Letters , To be left at the Royal Society V 
; Uoufe , in Crane-Court, in Fleetftreet, London, for the Secre- 
tary of the R OY AL SOCIETY. 
LOG O- 
