The Preface. vli 
And I hope the publication of this Speci- 
men of what I have hitherto done , will put 
others upon the fame purfuits , there being in 
fo large a field , and among fuch an innu- 
merable variety of fubje£ls, abundant room 
for many heads and hands to be employed in 
the work : For the wonderful and fecret ope- 
rations of Nature are fo involved and in- 
tricate , fo far out of the reach of our fenfes , 
as they prefent themfelves to us in their na- 
tural order, that it is impojfible for the mofi 
fagacious and penetrating genius to pry into 
them 9 unlefs he will be at the pains of ana - 
lyfing Nature, by a numerous and regular fie - 
ries of Experiments ; which are the only 
folid foundation whence we may reafonably 
expeffi to make any advance, in the real 
knowledge of the nature of things . 
I muft not omit here publickly to acknow- 
ledge, that I have in fever al refpeEls been 
much obliged to my late ingenious and learned 
neighbour and friend Robert Mather, of the 
Inner-Temple, Efq 5 for his affiftance herein. 
1 had intended to have inferted many ad- 
ditional Obfervations and Experiments , in 
their proper places , in this fecond Edition of 
this book : But for the fake of thofe who 
have- bought the fir ft Edition > it is thought 
mofi 
