t/a ae 
PHYSICAL ann LITERARY. 99 
force of cohefion, having oppofed the im- 
pinging body for fo fhort atime, makes no 
fenfible refiftance to it.’ The attraction of 
cohefion acting without interruption; any 
refiftance made, or any motion communica- 
ted by it, muft be gradually produced; and 
confequently, in avery fmall time, the ef 
fect will be proportionally {mall. Of this'we 
have many examples. Let us fuppofe a board 
fet nearly upright on its end, and fo flightly 
fupported, that a bullet thrown againft it, out 
of a man’s hand, will tumble it over; if the 
fame bullet be difcharged from a gun, it will 
go through the board without moving it out 
of its place. In the fame way, a bullet has 
been known to through a man’s body, an ° 
arm has been taken off by a cannon ball, or 
_ even by the fail of a wind-mill, without any 
_ vifible motion produced in the other parts of 
_ the body; though a much lefs force would 
- be fufficient to drag the whole body forwards. 
| The better to illuftrate the manner in which 
: _ thefe effects are performed ; let it be obfer- 
: wed, that by means of a fmall thread or a 
i Toad-ftone, a confiderable mafs of matter 
may be gently pulled alongft a table: where- 
as, if a fudden tug be given, or a greater 
force 
