CONTENTS. xiii 



IX. On the Decompofition of the Muriatic Acid. By Mr. John Pltchford, 

 Junior - - - % - p. 374- 



X. Obfervations on the A6lion which the Sulphate of Iron exercifes upon Ni- 

 trous gas, and on the Formation of Muriatic Acid. By Cit. BerthoUet 



p. 377 



Scientific News, Accounts of Books, &c. - - p. 379— 384 



Philofophical Tranfaftions of the Royal Society of London, for the Year 1800. Part the Second. 

 Foflil Wood, found at a very great Elevation. — Extra£l of a Letter from Mr. Humphry Davy, 

 dated Odlober 23. Supplementary to his Paper on Galvanifm, in the prefent Number. — Ana- 

 lyfis of various Foffils. — Lime in the Nut Call. — Extraftion of the Alkali of Sea Salt by Lime. 

 Method <A' obtaining Phofphorus by Phofphorate of Lead. — On the Mineral Kermes, and the 

 golden Sulphur of Antimony. — Elaftic Refin in Opium. — Difcovery of a New Earth in the 

 Beryl of Georgen-Stadt.— On the Method of hearing by the Teeth. 



DECEMBER 1800. 



Engravings of the following Objefts : 1 . Conftrudlion of a Wheel to reprefent 

 the Planetary Motions. And, 2. Method of graduating the Hydrometer, fo 

 as to indicate the Strength of Spirit by Infpeftion at any Temperature, 



I. On the Number of the Primitive Colorific Rays in Solar Light. By the Rev. 

 Matthew Young, D. D. S. F. T. C. D. and M. R. I. A. p. 385 



Whether the primitive colours be compofed of three original tints or more ? cannot be determined 

 by mixture of powders, &c. That light of one colour is not all of the fame refrangibility,' is 

 inferred from the extent of each colour on the fpeftrum. Probability that red, yellow and blue 

 are the primitive colours, becaufe any two of thefe adjacent to each other will compofe the 

 intermediate tinge ; though thefe fuppofed originals cannot be fo compofed of the others. The- ' 

 oretic obfervations, experimental teft of this dodtrine by coloured glafles. Ocular fpeflra. Hy- 

 pothefis of three colours will folve the phaEnomena of chromatics. 



II. An Account of fome Additional Experiments and Obfervations on the 

 Galvanic Phenomena. By Mr. Davy, Superintendant of the Pneumatic 

 Inftitution. Communicated by the Author - p. 3'94 



Sulphuric acid excites (he pile very little, but becomes aflive by the addition of water. Liquid 

 fulphurets are equal in power to water. Nitric and fulphuric acids aft in vacuo. Obferva- 

 tions, &c. Enquiries to determine what happens in the pile itfelf. Examination of the power 

 of difTcerent Galvanic combinations. 



lU. On the Quotients arifing from the Divifion of an Unit by prime Numbers. 

 By H. Goodwyn, Efq. ... p. 402 



IV. Conftruftion of a Wheel adapted to exprefs, by its Rotation, the unequal 

 ^gular Motion of the Planets, By M, Roemer - p. 404 



V. On 



