C 329 ) 
PHILOSOPHICAL 
TRANSACTIONS. 
^u/te 22. 167s. 
The CONTENTS. 
A Nevi^ B^/zj IftfirHment invented mi defcrilfed by the Honourable * 
Robert Boy ie, together with the Ufes thereof i The Difcourfe 
eonjifis of three parts ; Jhe fiva jbews the Occafion of making it^and 
the Hydrojlatical Principle *tis founded on ; The Tecond defcribes 
the ConpuStion of the Inftrument j The third represents the Ufes , 
which ^ oi relating to ^M^talsy are \ i.To difcover ^whether a pro- 
ofed G\my be true or count erf ait. 2. To examine divers other 
Gold'coyns^ and particularly half- Guiny s. 3 To examine the new 
Englijh Crown-pitccs of Silver. 4* To ejlimate the goodnefs of 
Tin and Pewter. 5. To efiimate Alloys of Gold and Silver, 
and fome other ^jl^etallin mixtures. 
The firft Seftion. 
Shewing the Occajion of rnakingthis new Ejfay-lnfirument^ together 
with the Hjdrojlatical Principle 'tis founded on, 
TO give you «wamore explicite and particular Accounr, 
than I had then time to do,of the Inftrument which you faw 
tried at the Royal Society, I lliall inform you, on what Grounds I 
devis'd it, and then annex fome Obfervations about the Fabrick 
and the Ufes of it. 
You may remember, that many years ago Ilhew'd you a little 
glafs-Iaftrument, confiftingofabubble, furniflied witha longand 
flender ftem, whichwas to be put into feveral Liquors, to com- 
X X pare 
