Royal Society. 393 



M.D. Sec. R.S.— 2G. On the Nature of tlia Salts termed triple 

 Prussiates, and on Acids formed by the union of certain Bodie* 

 with the Elements of thf Prussic Acid. By Robert Porrett, 

 jun. Esq. Communicated by William Hyde Wollaston, M.D. 

 Sec. R.S. — 27. Some Experiments on the Combustion of the 

 Diamond and other carbonaceous Substances. By Sir Hum- 

 phry Davy, LL.D. F.R.S. V.P.R.I — 28. Some Account of the 

 fossil Remains of a!i .A.nimal more nearly allied to Fishes than 

 any of the other Classes of Animals, By Sir Everard Home, 

 Bart. F.R.S. — 29. On an easier Mode of procuring Potassium 

 than that which is no.v adopted. By Smithsou Tennant, Esq. 

 F.R.S. — oO. On the Influence of the Nerves upon the Action 

 of the Arteries. By Sir Everard Home, Bart. F.R.S. — 31. On 

 the Means of producing a double Distilhition by the same Heat. 

 By Smithson Tennaiit, Esq. F.R.S. — 32. An Account of soma 

 Experiments on Arterial Heat. By Johu Davy, LL.D. F.R.S. 



LXL Proceedings of Learned Societies. 



ROYAL SOCIETY. 



Nov. 10. JL HIS evening t'le Society assembled after the long 

 vacationj the Right Hon. President in the chair. A letter 

 from Dr. Brewster to the President was read, detailing his farther 

 observations on the glass drops, called Rupert's. According to 

 Dr. B's experiments heated glass asj^umes a crystalline form at 

 a certain temperature, and the specific gravity of unannealed 

 glass is different from that of annealed. 



Nov. 17. A p"aper by Dr. Roget was communicated by Dr. 

 Wollaston, and read to the Society, describing a newly invented 

 instrument on the principle of the sliding rule, for facilitating 

 arithmetical calculations. It embraces all the advantages with- 

 out the defects of the sliding rule and Gunter's scale; but as the 

 paper was accompanied by drawings, a verbal description would 

 not be intelligible. The idea was perhaps derived from Dr. 

 Wollaston's scale of chemical equivalents, and only more exten- 

 sively applied 



Nov. 24. Part of a Letter addressed to the President by Dr. 

 JBrewster was read, containing a view of the author's numerous 

 e.\pcrinients on the depolarization of light. Almost every sub- 

 stance, anini;il, vegetable, and mineral, has been operated on by 

 Dr. B., and all except muriate of soda and tjpinelle ruby, de- 

 polarized light in every direction. 



The Society then adjourned till the annivcr>-ary on the 30th 

 of November. 



LXII. Li' 



