XXVI ROYAL SOCIETY OF CANADA. 



Report of Section III. 



The number of members of the Section in attendance was twelve. Of the absent members, JIi-. 

 Baillairgé, and Professors Cherriman and McGregor forwarded papers to be read. The other absent 

 members were Capt. E. Deville, Professor N. F. Dupuis, Mr. Sandford Fleming, Mr. F. W. Gisborne, 

 and Professor Harrington. 



Tlie Officers elected for the ensuing year were: — 



Mu. C. Carpsiael, President. 



Mr. T. Macfarlane, Vice-President. 



Mr. G. C. Hoffmann, Secretary. 



The accompanying list gives the title of the papers read in fall or in abstract, or accepted as 

 read : — 



I. Presidential Address. By Dr. A. Johnson. 



II. On a Natural System in Mineralogy with a Classification of Silicates. B3- Dr. T. Sterry 

 Hunt. 



III. Blowpipe Eeactions on Plaster Tablets. By Dr. B. Haanel. 



IV. On the Quantitative Blowpipe Assay of Cinnabar. By Dr. B. Haanel. 

 V. The following by Prof. J. P. Loudon : — 



1. Clausius' Theory of the Virial. 



2. The Motion of a Rigid Body with One Point Fixed. 



3. The Equation of Energy on Generalized Coordinates. 



4. Geometrical Methods in Optics. 



VI. On the Longitude of Toronto. By Mr. C. Carpmael and Prof. McLeod. 

 VII. Communicated by Dr. A. Jounson : — ■ 



1. On the Longitude of the Transit Instrument at the Observatory, McGill College, 

 Montreal. By Prop. W. A. Rogers, of Harvard, Mass., and Prof. McLeod, of 

 McGill College, Montreal. 

 . 2. On the Longitude of Cobourg. By Prof. McLeod and Mr. Chandler. 

 VIII. On Tidal Observations in Canadian Waters. By Dr. A. Johnson. 

 IX. On the Analysis of Silk. By Dr. H. A. Batne. 

 X. On the Geognosy of Crystalline Rocks. By Dr. T. Sterry Hunt. 

 XI. On the Determination in Terms of a Definite Integral, etc. By Mr. C. Carpmael. 

 XII. Verbal account by V. Rev.'T. B. Hamel of a paper by Dr. D. Duval, entitled: "Mémoire 

 sur l'introduction et l'interfjrétation rationelle des quantités négatives et des quantités 

 imaginaires dans le calcul." 

 Xill. On some Iron Ores of Central Ontario. By Prof. E. J. Chapman. 



XIV. Concernant la théorie de M. Steckel sur la veine liquide contractée. By M. C. Baillairgé. 

 XV. The Density of Weak Aqueous Solutions of certain Salts. By Prof. J. C. MacGregor. 

 XVI. A Commentary on Section IX of Newton's Principia. By Prof. J. B. Cherriman. 



Alexander Johnson, President. 

 G. C. Hoffmann, Acting- Secretary. 



Report of Section IV. 



The papers whose titles and authors are enumerated below were read either in extenso or by 

 title':- - 



I. On a new Mesozoic Flora discovei'ed by Dr. G. M. Dawson in the Rocky Mountains. By 

 Sir William Dawson, LL.D., F.R.S. 



