OF MERCURY. 403 



are anhydrous, and the rest contain 1, 2, or 4 

 atoms of water. 



Six species, viz. Diprotonitrate, protocarbo- 

 nate, protophosphate, protarseniate, protochro- 

 mate, and prototartrate, are anhydrous one, the 

 oxalate, contains 1 atom water two, the proto- 

 sulphate and protonitrate, contain 2 and one, 

 protacetate, contains 4. 



(2.) PERSALTS OF MERCURY. 



1. Persulphate of mercury. This salt, accord- Persul - 

 ing to the observations of Fourcroy, which are 



to a considerable extent correct, exists in vari- 

 ous states ; but the neutral salt is the beautiful 

 yellow powder, known by the name of turpeth 

 mineral, or queen's yellow. It is a tasteless in- 

 soluble powder, the constituents of which are 



1 atom sulphuric acid . 5 



1 atom peroxide of mercury 27 



32 



2. Bipersulphate of mercury. In white irre- Bipers 

 gular crystals. I found them composed of 



2 atoms sulphuric acid 



1 atom peroxide of mercury 



1 atom water 



38-125 



3. Pernitrate of mercury. This is a beautiful 



Cc2 



