1835.] the Advancement of Science. 199 



2. K (C +' C) H (C + C) HS or binoxalate ; decomposes 

 at 300° and loses 2 atoms. 



3. K (C + C) H ^ H (C + C) H2 



c H (C + C) H2 or quadroxalate, the 2 

 atoms of water in the binoxalate being replaced by hydrated 

 oxalic acid. 



There are two remarkable salts, which correspond with 

 each other in composition, viz., oxalate of potash and iron 

 which is green, although the iron is in the state of per- 

 oxide, being precipitated red by potash, and the oxalate 

 of potash and chromium which is dark coloured. The 

 first is represented by Fe (C + C)^ 3 K (C + C) + H^. 



If we substitute chromium for iron, we have the compo- 

 sition of the chromium salt. 



The same law in reference to water, it is probable, is 

 generally applicable to the composition of the carbonates. 

 Carbonate of magnesia is represented by Mg CH^. At 

 212° the water is expelled. 



Bicarbonate of potash =K C H Cis a carbonate of potash 

 and a carbonate of water, because the latter can be readily 

 driven off. Two additional atoms of water may exist in it. 

 The bicarbonate of potash and magnesia of Berzelius, has 

 the same composition as quadroxalate of potash, the symbol 



being K C H C f M^- 9 ^"^ ^ + H* making 9 atoms of water 



in the salt, and the magnesia occupying the place of the 

 water in the quadroxalate of potash. 



Rose described a class of salts formed by the absorption 

 of dry ammonia. He considered the ammonia not to act 

 as a base, but to take the place of water. 



Mr. Graham coincides with him in opinion. The compo- 

 sition of ammonia may be represented byNH^NH^HO, 

 being analogous to sulphuric ether, which consists of 2 atoms 

 olefiant gas. The nature of its function maybe observed 

 in the composition of the common sulphate of copper and 

 ammoniacal copper, the first is, Cu S H + H^, the second 

 Cu S H + (N H3) 4 the ammonia taking the place of the 

 water. There are 2 ammoniurets, 1 containing 4 and the 

 other 5 atoms of water. 



8. Mr. Johnston made some observations on the optical 

 properties of chabasite, in reference to those made by Sir 



