46 C. H. Palmer — Bemarkable Case of Hijdration. 



more, and to 19-60 per cent after 24 hours at 100° C. After 

 this, the platinum dish containing the substance was allowed to 

 sit in the balance case for 48 hours, during which time it not 

 only regained all its previous loss but 0*68 per cent in addition, 

 and all this, too, without a perceptible change in color or 

 general appearance. 



The total loss by heating at a low red heat to constant weight 

 was 27*28 per cent. Analysis of the sample gave the following 

 results : 



Silica __ _ _ 35*84^ 



Cupric oxide .._. _ 31-50 



Alumina 3 •'74 



Ferric oxide trace 



Manganese oxide " 



Calcium oxide 1*76 



Magnesium oxide 0*16 



Water (over H^SO J _ 1 8*96 



Water (at low red heat) ._ 8-32 



100-28 



Another sample (No. 3) of dark green material from the 

 Pinal ore was found, which occurred as an incrustation about 

 one-eighth of an inch thick, and which appeared no less pure and 

 even richer in copper than the last. It lost 15*60 per cent over sul- 

 phuric acid in 24 hours, this being increased after 11 days to 20*54 

 per cent. The dish containing the substance was then placed 

 in a dessicator over water. In 21 hours it had made up all its 

 former loss and 2*64 per cent besides, and after four and one-half 

 days more under the same conditions, this increase amounted to 

 5*14 per cent, making a variation of 25*68 per cent in the amount 

 of water at ordinary temperature with no change whatever in 

 appearance. The loss at 100° C. was 20*72 per cent, being but 

 very little higher than the loss over sulphuric acid, and the total 

 loss at a red heat was 29*14 per cent. The analysis of this 

 material, of which only about 1*5 grams were obtainable, is as 

 follows (calcium and magnesium being present but not deter- 

 mined cpiantitatively ) : 



SiHca.._ 33-28,^ 



Ciipric oxide — 30*76 



Alumina 4-60 



Ferric oxide - trace 



Manganese oxide trace 



Calcium oxide _ not det. 



Magnesium oxide -.. not det. 



Water (over H^SOJ 20*54 



Water (at low red heat) 8*60 



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