- PHYSICAL and LITERARY. 41 
 folids equally. Here then is a fair dilemma. 
We mutt either acknowledge a preffure un- 
a dequaque in fand, powder, and indeed in all 
- loofe bodies, as well as in fluids; or confine 
this law of the equality of action and reacti- 
onto fluids. Can we remain a moment in 
4 doubt betwixt thefe oppofites? We are cer- 
_ tain that a preflure undequaque is not a pro- 
 perty of folids. ~The equality of action and 
reaction is but an affertion without evidence. 
What remains then, but that we adhere to 
the former, and reject the latter, except as 
to fluids. And thus our author luckily, tho’ 
without intention, has furnifhed a very con- 
vincing argument againft the univerfality of 
this fuppofed law of action and reaction. If 
an undequaque preflure is an effect of this law, 
it follows clearly, that this law takes not’ 
place in folids, at leaft not univerfally, as in 
fluids. 
