460 S. B. Christy— Genesis of Cinnabar Deposits. 
This amount was contained in a bottle of two pounds. 
Sulphydric acid was passed into this water for half an hour, 
an equal amount of mineral water, and some black mercuric 
sulphide were added to it, and the mixture was treated in the 
digester, while a similar experiment was carried on at the ordi- 
nary pressure of the atmosphere and a temperature of 100° C. 
The temperature of the digester was not more than 180° C., 
and the pressure 140 to 150 lbs. The time in both cases was 
two hours. The sulphide which was treated in the open air 
was unchanged even when examined with the microscope, 
while that treated in the digester was brownish red even to the 
naked eye, while under the microscope it showed itself to be 
nine of a small amount of as yet unchanged amorphous 
ide, and a larger amount that was completely transformed 
to cinnabar. Orystals were not visible with the powers used. 
This mineral water, therefore, when the single ingredient of 
sulphydric acid is added to it is capable of dissolving mercuric 
sulphide, and of depositing it from solution in the crystalline 
orm when it is slowly cooled. 
Fourtu.—Tue Rrvat THEORIES. 
more probably by bringing it from lower 
In support of this position are the following facts: In the first — 
place, cinnabar volatilizes only at just below a red heat (500° C.), 
when exposed to the ordinary pressure of the atmosphere. 
Now, if we take the increase of temperature as 1° C. for each 
100 feet below the surface, it would take a depth of nearly 
