CONTENTS OF VOL. XIII. 



NUMBER LXXIX.— JULY, 1838. 



Page 



Education of Students in Civil Engineering and Mining in the 



University of Durham 1 



Mr, R, Potter on the Radii and Distance of the Primary and 

 Secondary Rainbows, as found by Observation, and on 

 a Comparison of their Values with those given by Theory. . 9 

 Lieut. -Col. Emmett's Meteorological Observations taken at St. 

 George's, Bermuda, in the December half-year of 1837 ; in- 

 troduced by Corrections of Observations for the June half- 

 year 12 



Dr. Golding Bird's Experimental Researches on the Nature and 



Properties of Albumen, &c 15 



Prof. J. F. W. Johnston on the Composition of certain Mineral 



Substances of Organic Origin. No. V, Elastic Bitumen .... 22 

 Prof. J.F.W. Johnston on the Separation of the Oxalic from 



other Organic Acids 25 



Prof. R. Hare on the Reaction of the Essential Oils with Sul- 

 phurous Acid, as evolved in union with .^Ether in the Pro- 

 cess of -^therification, or otherwise 28 



Mr, C. HoltzapfFel on a Scale of Geometrical Equivalents for 



Engineering and other Purposes 32 



Mr, R. Laming on the primary Forces of Electricity 44 



Mr. C. Binks on some of the Phsenomena and Laws of Action 

 of Voltaic Electricity, and on the construction of Voltaic 



Batteries, &c 54 



The Herschel Dinner 75 



Action of Light on Solution of Cyanogen 77 



Bichromate of Perchloride of Chromium 78 



Meteorological Observations for May 1838 79 



Meteorological Observations made at the Apartments of the 

 Royal Society by the Assistant Secretary Mr. Roberton ; 

 by Mr. Thompson at the Gardens of the Horticultural Society 

 at Chiswick, near London ; by Mr. Veall at Boston ; and by 

 Mr. Dunbar at Applegarth Manse, Dumfries -shire 79 



NUMBER LXXX.-AUGUST. 



Mr. Ivory on the Conditions of Equilibrium of a Homogeneous 



Planet in a Fluid State 81 



Mr. Lubbock on a Property of the Conic Sections 83 



Mr. D. Waldie's Experimental Researches on Combustion and 



Flame ^6 



Prof. J. D. Forbes's Researches on Heat. Third Series 97 



Dr. J. Apjohn on a new Compound, consisting of Iodide of 



Potassium, Iodine, and the Essential Oil of Cinnamon 113 



Mr. T. Richardson's Researches upon the Composition of Coal 121 



a2 



