3 ;a COMBINATION OF MERCURY 



three times its weight of mercury, and fo quali- 

 fied, that its prefence cannot be deteded either 

 by tafte, or by the inlluence of reagents. In- 

 (lead of attrading moifture with any confider- 

 able force, it does not diflblve in water without 

 difficulty. Ihcfe circumftances, as they all a- 

 gree to prove the intimacy of the combination 

 between the acid and the mineral ; fo, inltead of 

 explaining, they rather concur to conceal more 

 entirely the caufe to which the mercury owes 

 its corrofivc powers, Yet, I cannot avoid praiiing 

 the ingenuity of Macquer, who, though he does 

 not altogether remove the difficulty, yet pro- 

 pofes a plaufible and natural theory *. Nature, 

 fays he, has difpofed all bodies to a mutual uni- 

 on. This natural tendency is commonly called 

 affinity or attractive force. Upon the heavenly 

 bodies it operates even at ii wntnfe ill Jlunccs ; but 

 on earth it ads between bodies, only when they 

 arc brought clofe together. Bcfides, the mutu- 

 al attradions of terreftrial bodies arc not regu- 

 lated merely by bulk and diflancc. The modes 

 and the degrees of chemical affinity arc very va- 

 rious. Some bodies even refufe to combine : 

 and this may happen, when the parts of any one 

 of two bodies have a greater tendency to adhere 

 together than to enter into combination with 

 the parts of the other. Mercury and the ma- 

 rine acid aflbrd an inftance; in their natural 



flat* 



* Dictionary of Chemiflry. 



