12 2 
Of viewing the Current 
The Way of applying it to the Microfcope 
was defcribed Page 13, and therefore needs 
not be repeated here. 
The Tails or Fins of fmall Fifhes may 
likewife be ufed very commodioufly to this 
Purpofe, and prefent to view great Num¬ 
bers of Veins and Arteries with the Blood 
palling different Ways through them. 
It is difficult here in London to meet with 
any Fifhes alive and proper for this Infpec- 
tion, except Eels and Flounders : either of 
thefe however will ferve exceeding well; 
but the fmailer they are the better.—-Put 
your E<?/into a Glafs Tube filled with Water, 
after wiping off its Slime, which would ob- 
fcure your Glafs. Then having flopped 
both Ends, to prevent the Water’s running 
out, apply the Tail or Fin to your Micro- 
fcope, and you will fee the Circulation in a 
very agreeable Manner. If you put not 
Water in your Tube, the Sliminefs of the 
Eel will immediately foul the Glafs and 
prevent your Pleafure. 
The flat Figure of the Flounder will not 
permit us to put it into a’Tube as we do the 
Eel, or view it by every Kind of Micro- 
fcppe : but if a plain Piece of thin Glafs be 
placed over the Hole where Objedls are ap¬ 
plied to the Double Receding Microfcope, 
its Tail may be fpread advantageoufly upon 
the faid Glafs; and by fetting a Book, or 
n . fome- 
1 
