[ 2C 4 1 [Book VI. 



C HAP. XXXIII. 

 MERCURY. 



Great Attraction of this l-.'L'ta! for the Matter of Heat. Quickfti'ver ; 



rendered folid ; malUalle General Properties of Quickfil-ver. Hy- 



drargyrus calcinates. Natural Hijiory cf Mercury. Cinnabar. 

 Native Vermilion. Aftion of Acids on this Metal. Turbitb Mine- 

 ral. Red Precipitate. White Precipitate. Corroji<ve Sublimate. 

 Calomel. Kcyfer's Pills. Ethiop's Mineral. Vermilion. Amal- 

 gams. Gold made brittle by Merctuy. Mode of gilding Metals. 

 V/e of ^uickfil'ver in extracting the precious Metals, from the Earth. 

 Making of Looking Glares. Conditions necej/ary for the Operation 

 cf Mercury on the human Body. 



TH E circumftance which moft remarkably dif- 

 tinguifhes mercury, or quickfilver, from the 

 other metals, is its ftrong attraction for caloric, fo that 

 it retains the ftate of fluidity at the ordinary tempera-- 

 ture of the atmofphere, and at the temperature of 600 

 degrees of Fahrenheit is converted into vapour; few 

 of the other metals, therefore, melt at fo low a point 

 as that at which mercury boils and is volatilized. It 

 was long taken for granted that there was fomething 

 peculiar in mercury, which rendered it neceffarily fluid ; 

 but the academicians of Peterfburgh have proved that 

 this is an erroneous idea, and have mewn that mercury 

 differs from oth'er metals merely in the degree of heat at 

 which it paries from its folid to its fluid ftate. The 

 congelation of mercury has been effected in a variety 

 of inftances by the help of the nitrous acid and fnow a 

 or pounded ice, commonly called the freezing mixture, 

 and > the congelation is found to take place at the 

 thirty-ninth degree below o of Fahrenheit's thermo- 

 meter. Mercury, in its folid form, is found to have 



confide rable 



