316 Chemical Society. 



per cent, of potassa, and 46'58 of oxalic acid. This agrees very well 

 with the formula for oxalomethylate of potassa, plus one atom of 

 water ; but no water could be driven out by a heat of 150° C, and I 

 at length found that the salt was only oxalovinate of potash, with 

 the composition of which the analyses agree very well : — 



1. 2. 



Oxalic acid . . . 46-12 46"58 



Potassa .... 3004 3076 30*81 . 



The salts agreed, moreover, completely in their properties. On re- 

 peating the experiment with wood- spirit instead of alcohol I did not 

 obtain an insoluble salt, but on evaporation one which is probably the 

 true oxalomethylate of potash, and which I am now about examining. 



Such a decomposition as the above is, I believe, of very rare oc- 

 currence ; I am not aware of any other instance of it being known, 

 although the possibility of some such kind of decomposition has not 

 escaped the acuteness of Berzelius. (Lehrbuch, viii. 703.) We may 

 perhaps suppose that oxalomethylate of potash is first formed, but 

 that the attraction of oxalic acid for aether, and of oxalic aether for 

 oxalate of potash is so strong as to cause the decomposition of hy- 

 drate of aether into its elements, when the alcoholic aether will com- 

 bine with the oxalic acid, and the oxide of methyl, whose place it 

 takes, combines with water to form wood-spirit. That some kind 

 of what is called predisposing affinity is here in play, is evident from 

 the fact that oxalate of methyl may be boiled with alcohol for hours 

 without any such change taking place. 



It may be stated, in conclusion, that the process last described is 

 a very good and oeconomical method of obtaining the oxalovinate of 

 potassa in a very beautiful form. 



" On the Radical of the Cacodyl Series of Compounds," by Pro- 

 fessor Bunsen of Marburg. (In Phil. Mag. S. 3. vol. xx. p. 382.) 



Jan.. 4, 1842. — The following- communications were read ; — 



" On some of the Substances contained in the lichens employed 

 for the preparation of Archil and Cudbear," by Edward Schunck, 

 Esq. (This paper will be found in Phil. Mag. S. 3. vol. xx. p. 495.) 



" On a re-arrangement of the Molecules of a Body after soli- 

 dification," by Robert Warington, Esq. (Inserted in Phil. Mag. S. 3. 

 vol. xx. p. 537.) 



Jan. 18. — Colonel Yorke exhibited a specimen of a silver ore from 

 Mexico, containing bromide of silver, from his collection, in confir- 

 mation of the late discovery, by M. Berthier, of the existence of 

 bromine in silver ores. 



The following communications were read : — 



" On the Conversion of Benzoic Acid into Hippuric Acid, in the 

 Animal Economy," by Mr. Alfred Baring Garrod, of University Col- 

 lege. (In Phil. Mag. S. 3. vol. xx. p. 501.) 



' On the Constitution of the Sulphates, as illustrated by late 

 Thermometrical Researches," by Thomas Graham, Esq., F.R.S. (In 

 Phil. Mag. S. 3. vol. xx. p. 539.) 



February 1 . — The following communication was read : — 



'* On the Change of Colour in the Biniodide of Mercury," by 



