599 



curate and satisfactory results, perhaps even more so than the com- 

 mon form of barometer, but that there is considerable uncertainty- 

 attached to its indications. This uncertainty, far from being "vvholly 

 attributable to the imperfections of the instrument as a measure of 

 the atmospheric pressure, might, the author thinks, arise from an 

 extreme susceptibility to rapid changes in that pressure, which re- 

 main unindicated by the more sluggish barometer. 



" On the Decomposition and Analysis of the Compounds of Am- 

 monia and Cyanogen." By Robert Smith, Esq., Ph.D. Communi- 

 cated by Captain William Henry Smyth, E.N., F.R.S. 



This paper is divided into four parts ; the first relates to the de- 

 composition of ammonia and its compounds by the compounds of 

 chlorine, and the collection and measurement of the nitrogen gas 

 which is disengaged, the amount of which the author considers as 

 furnishing a ready and accurate mode of estimating the quantity of 

 ammonia in the solution subjected to analysis. The chloride of lime 

 was the salt usually employed for this purpose : this method is re- 

 garded by the author as being peculiarly applicable to the analysis 

 of organic substances. 



The second part treats of the decomposition and estimation of 

 hydrocyanic acid and its compounds by means of chloride of lime, 

 yielding nitrogen gas and carbonate of lime; a process which occu- 

 pies but a few seconds. In some cases, the employment of chloride 

 of soda is preferable to that of chloride of lime, on account of the 

 solubility of all the compounds that are formed. The author found 

 the same method applicable also to the analysis of the salts of cya- 

 nogen ; for the cyanides of the alkalies are decomposed by it as 

 rapidly as the pure acid itself. The ferro-cyanides are also very- 

 readily decomposed. 



The author, in the third part of his paper, relates the results of 

 his trials of the hypochlorites as agents for the decomposition of uric 

 acid, which proved so satisfactory as to induce him to believe that 

 these salts might be advantageously used as solvents of uric calculi 

 in the living bladder. He also proposes the employment of chloride 

 of lime as a ready and accurate mode of estimating the quantity of 

 nitrogen contained in urine, from the amount of gas disengaged by 

 its action on the nitrogenous compounds. ]n the last part, the ap- 

 paratus used in the experiments is described. 



" On a point connected M ith the dispute about the invention of 

 Fluxions." By Augustus De Morgan, Esq., M.A., F.R.A.S., &c. 

 Communicated by Samuel Hunter Christie, Esq., Sec. R.S., &c. 



An assertion made by Sir Isaac Newton in a letter to Conti, pub- 

 lished in Raphson's History of Fluxions, that the materials of the 

 Commerciiim Epistolicum were " collected and published by a nu- 

 merous Committee of gentlemen of differejit 7iations, appointed by 

 the Royal Society for that purpose," appeared to be at variance with 

 the list of the Committee as it was appointed on the 6th of INIarch, 

 1711-12, and which only contains the names of Arbuthnot, Hill, 

 Halley, Jones, Machin and Burnet, who were all English. But on 



