BRITISH ASSOCIATION. 



267 



metals. He had shown that these peroxides possessed 



the formula O4 and not R 



Taking the case of copper, we have the series 



O— Cu O— O3--CU2 O4. 



In all these oxides, the copper unites in two atoms, except 

 in the case of the protoxide. But by doubling the atom, 

 we would have a uniform series^ — 



CuO— CuOo— CuOg— CUO4 

 — the oxides in this case increasing the arithmetical progres- 

 sion. He showed, that in many of the salts, there was 

 evidence of this double atom. Sulphate of copper absorbed 

 2| atoms of ammonia ; a sulphate of lime was known with ^ 

 an atom of water, &c. 



Professor Graham said, that chemists had long looked for these 

 oxides with much anxiety, and nothing could be more welcome than 

 their discovery, as they would serve to clear away many objections to the 

 doctrine of isomorphism. 



Dr. Daubeny thought the close analogy shown between water and 

 oxide of copper of much importance, in confirming the views originally 

 proposed by the President (Prof. Graham) . 



Dr. Apjohn stated, that he had on one occasion obtained a hydrate 

 of the peroxide of manganese in beautiful crystals. He was unable to 

 state from memory, the proportion of water which it contained, but 

 thought its correct examination might be of some use in connexion with 

 Dr. Playfair's views of the important functions of water in the peroxides 

 described. 



Dr. Daubeny read a paper " On the Causes of the Irregu- 

 larities of Surface ivhich are observable in certain parts of 

 the Magnesian Limestone Formations of this Country*^ 

 The magnesian limestone rocks in some of the quarries in 

 Derbyshire, presents a remarkable appearance. They do 

 not possess an undulating surface, as the limestones gene- 

 rally do, but the surface is covered with irregular elevations 

 and depressions of a very marked character. Prof. Sedg- 

 wick had cursorily noticed the configurations which these 



