33 



TAB. CCCLI. 



CUPRUM sulphatum. 

 Sulphate of Copper, or Blue Vitriol. 



Class 3. Metals. Order 1. Oxygenized Compounds. 



Gen. 12. Oxide of Copper. Spec. 3. Sulphate. 

 Div. 1. Crystallized. 



Spec. Char. Oxide of Copper combined with Sul- 

 phuric Acid. 

 Syn. Vitriol of Copper. Kirw. 2. 22. 

 Cuivre sulphate. Haily, 3. 580. 



According to my specimens, which I have had many 

 years, this is found in those rocks which are usual in North 

 Wales, in which Cubic Pyrites so much abound, and is 

 occasionally adulterated by the Iron. Tt is most pure when 

 nearly deep blue with a greenish cast ; but is sometimes 

 lighter coloured, as figured. It is less soluble than Sul- 

 phate of Iron, requiring four times its weight of cold water, 

 and twice its weight of boiling water for solution ; it is also 

 styptic to the taste. It may be artificially procured of a 

 vivid and rich blue; but always having a greenish cast. 

 The upper figure gives the most usual appearance of it 

 upon the rock. The specimen figured below was, when 

 first gathered, of the beautiful blue cast of the fresh 

 broken inner part} probably some Oxide of Iron is the 

 cause of the outward change of colour, which, however, 

 doest not penetrate far into it. The best Crystals are formed 



