3 N To the Honourable 
Robert Boyle Efq; 
EFTER I had finifhed the foregoing 
ES Books, In which, 1 conceive, as far as 
part, to Vufold the Reafon and Scope of Nature there. 
in: I was willing to fit down, and leave what remained, 
f the to the Improvements of the Prefent and Succeeding 
Ages. 
But in Difcourfe upon this Subjeät, You have been pleafed 
frequently to infifl, That I fhould by no means omit, to give 
likewife, fome Examples of the Mechanifme of Nature in 
all the other Parts. The Performance whereof therefore, 
next to the Obedience I owe to the Royal Society, is to 
be looked upon, as a Due to the Authority which Your Jude- 
ment hath over me. 
This I have faid, that, if what is herein done, hall prove 
acceptable unto Learned Men ; they may know, To whom they 
4 are oncemore to give their Thanks: After they have fo often 
ther done it,upon (a better fcore) the Publifbing of Your own Ex- 
cellent Works. In which, there feems to be a Queflion, Whe. 
ther Your Continual Endeavours, to enlarge the Bounds of 
Natural Knowledge, or Zour Succeffes therein, have been 
the Greater: So that; whereas Nobility in fome, doth 
only 
Gon of 
