The PREFACE, xxi 
Cafes, by fliewing not only the Na- 
ture, but alfo the Caufes which are 
mofl: apt, either to promote or re- 
tard the Progrefs of this Secret and 
terrible Intruder ; not that it is to be 
expelled, that all fhould find Bene- 
fit thereby, tho’ haply fome may. 
The. Inftrument defcribed at the End 
of this Treatife, will, I doubt not, 
be very beneficial in inftantly reliev- 
ing many, who might otherwife buf- 
fer great Torture for feveral Days, 
and fome of them lofe their Lives 
by a dangerous Incifion. 
The App.endLx contains feveral 
mifcellaneous Obfervations and Ex- 
periments, fome oi which relate tq 
Subjefis in F egetable Staticks, but 
the greatefl: Part to the Analyji^ of 
the Air in the fiijfl; Volume. 
I have added a general Index of 
the Matters contained in thefe two 
a 3 Volumes. 
