CONTENTS. ix 



Enquiry whether light be unequally reflexible in the fenfe of Sir Ifaac Newton. From an examina- 

 tion of the circumftances it is fhewn that the efFeft defctibcd by Newton was produced by a real 

 difference in reflexibilitj', and not in confequence of refraflion at the firil furface of the prifm, as 

 Mr. Brougham has aflerted. Examination of Mr. Brougham's experiment with a vertical prifm. 

 Enquiry whether the different rays of light be differently reflefted in Mr. Brougham's acceptation 

 of the terms ; that is, whether the angles of incidence and refleftion be in any cafe unequal. It is 

 fliewn by a diagram, tiiat the effefls obferved by Mr. Brougham, may be accounted for by his own 

 hypothefis, that the red ray is more ftrongly repelled than the violet, without having recourfe to 

 the fuppofitipn that the angles of incidence and refledion are unequal. 



X. On the Manufadlnre of the Beech Oil, by Aaron Hill ; and other Projefts 

 of Improvement. By a Correfpondcnt - - p. 229 



Accounts of the invention of the flocking-engine, and a number of other projefls. Hilfory of the 

 manufaflure of oil from the beech-nut, at the rate of two gallons per bufhel. Attempts at the 

 eftablifhment of a trading company for this article. 



XI. Letter from Mr. Troughton rcfpe(fling a Balance of his Conftrudllon p. 233 

 Scientific News. Account of Books, &c. ' 



Kirwan's Geological EfTays. Buee's Mathematical Enquiries concerning the Texture of Bodits. 

 Death of Galvani. On the Acouflic Experiments of Chaldni and Jacquin. New fulminating 

 Mercury. 



SEPTEMBER i799. 



Engravings of the following Objedts : i . The apparent Attradlions of Floating 

 Bodies: and, 2. Keith's Sclf-regiflering Thermometer. 



I. A circumftantial Defcription of the Method of cultivating the white Beet 

 (Runkelrube), in order to obtain the greateft Quantity of Saccharine Matter, 

 and to prepare it for the Manufafture of Sugar. By F. C. Achard, Diredtor 

 of the Phyfical Clafs in the Royal Academy of Sciences - p. 237 



Defcription of the plant. Great variations in the faccharine produft. Influence of culture upon 

 that prodwft. Inftrudions and eftimates. General remarks. 



II. Appendix to Sir George Shuckburgh Evelyn's Paper on the Means of af- 

 certaining a Standard of Weight and Meafure - - p. 243 



Determinations of the lengths and comparative accuracy of feveral fcalfis of length. 1 . That ufed by 

 General Roy; 2. That of Mr. Aubert; 3. That of the Royal Society; and, 4. The ftandard of 

 Henry VII. Reduflion of thirteen feveral fcales of authority to the meafure of Troughton. 



IIL Obfervations on the Manners, Habits, and Natural Hiftory of the Ele- 

 phant. By John Corfe, Efq. (Continued from page .197) - p« 247 



Interefting fads and refults concerning the fexual intercourfe and propagation of the elephant. 



IV. Extradt of a Letter on the Art of Bleaching, and the Effeft of Fridion in 

 Water- courfes for Mills. By a Correfpondcnt - - P> 252 



Vol. Ill ^March 1800. ' c V. 



