428 ZINC, CADMIUM, LEAD, c. 



and being carefully collected and weighed, 

 amounted to 27 grains very nearly. 



The liquid, thus freed from mercury, was neu- 

 tralized by nitric acid, and being mixed with ni- 

 trate of barytes, a precipitate of sulphate of 

 barytes fell, which, after being washed, dried, 

 and heated to redness, weighed 6 grains, equiva- 

 lent to 0-81 grains of sulphur. Thus, we have 

 obtained from 29 grains of cinnabar 



Peroxide of mercury . 27 

 Sulphur . . . 4-01 



31-01 



This exceeds the quantity analyzed by 2 grains. 

 The reason is, that in the cinnabar the mercury 

 is in the metallic state, while in the analysis it 

 was obtained in the state of peroxide : but 27 

 peroxide are equivalent to 25 in the metallic 

 state. Hence, cinnabar is a compound of 



Mercury . . 25 



Sulphur . . 4-01 



29-01 



* 



The O01 grain of excess is, doubtless, owing to 

 an error in the analysis ; which, with all my care, 

 I was not able to avoid. But I consider the 

 analysis as proving that cinnabar is a compound 

 of 



