1814.] Royal Society. 6? 



conversation, &c. all which disappear when the cause 13 removed. 



7. Internal pressure from tubercles produces similar effects. 



8. Hydatids in the brain occasion bowel complaints, and a comatose 

 state of tbe rectum and bladder. 9. Wounds in the brain occasion 

 no symptom whatever, nor the destruction of any of the faculties. 

 When a fungous excrescence of the brain takes place through a 

 hole in the scull, the esophagus becomes so sensible as to prevent 

 swallowing solids, from the pain which they occasion. 10. Injuries 

 of the spinal marrow in the neck occasion paralysis of all the parts 

 of the body below the injury. 



On Thursday, the 9th of June, a paper by Sir Humphry Davy 

 was read, containing additional observations on iodine. The paper 

 consisted of five parts. Part first contained additional observations 

 on the triple compounds formed by dissolving iodine in solutions of 

 alkalies and alkaline earths. The author had already ascertained 

 that when iodine is dissolved in a solution of potash two different 

 substances are formed; the first a compound of oxygen, iodine, and 

 potassium; the second a compound of iodine and potassium. The 

 first of these compounds, which is analogous to hyperoxymuriate of 

 potash, is nearly insoluble in water. To obtain it pure, it must be 

 boiled repeatedly in alcohol, which dissolves the iode of potassium, 

 but leaves the triple compound, to which Davy gives the name of 

 oxiode of potassium. This substance dissolves in sulphuric, phos- 

 phoric, acetic, oxalic, and indeed in all the acids tried, without 

 undergoing decomposition. At a red heat it gives out oxygen gas, 

 and sulphuric acid poured upon the remainder expels iodine, while 

 sulphate of potash is formed. From two analyses, but both upon 

 a very small scale, Davy concludes that this salt is precisely 

 similar in its composition to hyperoxymuriate of potash, onlv that 

 iodine comes in place of chlorine. Oxiode of sodium is analogous 

 in its properties to oxiode of potassium. Oxiode of barium is 

 nearly insoluble in water. The author did not succeed in his 

 attempts to obtain a separate compound of iodine and oxygen. 



Part second consisted in experiments on hydrionic acid. This 

 acid dissolves iodine, and forms an orange coloured solution. It 

 absorbs oxygen from the atmosphere. The compounds which it 

 forms with bases are very similar to the analogous muriates. When 

 oxygen is present they are decomposed by heat, iodine being dis- 

 engaged ; and potash, lime, or whatever constituted the basis, lelt 

 behind. 



On Thursday, the l(>th of June, the remainder of Sir Humphry 

 Davy's paper on iodine was read. In the third part the author gave 

 an account of his experiments on the combination of iodine and 

 chlorine. When iodine is heated in a dry vessel filled witli chlorine 

 gas it absorbs about one third of its weight of that gas, 'I he com- 

 pound formed dissolves in water, forming a very acid liquid, which 

 in the author's opinion owes its acidity to the properties of this 

 chloride of iodine, which of course he considers as an ;icid. V\ lieu 

 agitated in chlorine gas, this substance becomes colourless. It has 



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