TABLE OF CONTENTS 



TO THIS SEVENTH VOLUME, 



JANUARY, 1804. 



Engravings of the following Obje£ls: 1. The Station-Pointer of Jofeph Hadf 

 dart, Efq. F. R. S. by which the Situation of a Ship or Veffel is very precilely 

 determined from Two Horizontal Angles ; 2. A Scheme, by Mr. Dalton, for 

 fliewing the Pjftribytion of the Particles of mixed Gafcsj 3. Diagram to fliew 

 the Method of conftru6ling and computing the Situation of an Obferver from 

 the angular Pofition of Three known Obje^s j 4. A double Barrel and Winch,, 

 for increafing the Power without any Diminution of Strength ; 5. A Screw-" 

 Prefs, which, by the contrary Aflion of Two Helical Threads, affords a sreat 

 Increafe of Power at the Place of the moft extreme Preffure ; 6. A Pumpa^- 

 ing by the Difference of Two Cylinders} 7. Alphabetic Syftem for writing in 

 the Dark, by Mr. John Gdugh. 



I. Defcription and Ufe of the Station -Pointer; an Inftrument for readily af- 

 certaining the Situation of the Obferver, after having determined the angular 

 Pofition of Three known Objefts j coniiru6led by Jofeph Huddart, Efq. 

 F. R. S. and communicated by him to the Editor. - - 1 



JI. Experimental Effays on the Conftitution of mixed Gafes 5 on the Force of 

 Steam or Vapour from Water and other Liquids in different Temperatures, 

 both in a Torricellian Vacuum and in Air j on Evaporation j and on the 

 Expanfton of Gafes by Heat. By John Dalton. - - - 5 



in. Obfervaiions on the Cultivation and Growth of Oak Timber. In a Letter 

 from the Rev. Richard Yates, F. A. S. Chaplam to his Majelty's Royal Hof- 

 pital at Chelfea, to Charles Taylor, Elq. Secretary to the Society of Arts. 17 



IV. A Firft Memoir on coloured Shadows. By Cit. J. H. HafTenfratz. 23 



V. Account of the Preparation of the Hyacinthus non Scriptus, or commoa 

 Blue-Bell, as a Subllitute for Gum- Arabic. In a Letter from Mr. Tho. 

 Willis of Lime-Street, London, communicated to Charles Taylor, Efq. 

 Secretary to the Society of Arts. - - - - 30 



VI. A Memoir on Vinous Fermentation. By Cit. Thenard. - 33 



VII. Conje6lures refpefting the Formation of the Ice in the Cavern of Grace 

 Dieu. By C. L. Cadet, of the College of Pharmacy. - - 44 



VIII. Obfervations on the Stru6ture of the Tongue j illuftrated by Cafes in 

 which a Portion of that Organ has been removed by Ligature, By Everard 

 Home, Efq. F, R. S. - - - - - - 47 



IX. Account of Three Mechanical Stru6lures not commonly noticed or known, 

 in which the Effc6l is produced by the Difference between the Aftions of Two 

 fimple Inftruments of the fame Defcription j namely, 1. a compound Barrel 

 and Winch; 2. a compound Screw; and 3. a compound Pump, W. N. 59 



X. Scoteography, or the Art of Writing in the Dark. In a Xetter from Mr. 

 John Gough. ------^53 



XI. Method of uniting Sulphur and Phofphorus without Danger to the Ope- 

 rator, and an. Attempt to explain the Change that then takes place. By 

 Robert Briggs, M. D. Edinburgh. Communicated by the Author. 5^ 



XII. On the beft Method of afrertaining the Dip at Sea. In a Letter from Mr; 

 Ezekiel Walker. -.-.-. 52 



XIII. New Procefs for fabricating Alum artificially, and without the Afliftancc 

 of Evaporation, By Cit. Curaudau, Correfponding Member of the Society 

 of Apothecaries of Paris. ----- 63 



XIV. Letter from Mr. John Farcy, concerning the great Fiery Meteor of No- 

 vember 13, and on other Subje6ls. - . _ - (^5 



XV. Method of reftoring rancid Effentlal Oils. By J. B. De Roover. 6$ 



XVI. Queftions, 1. refpefting the Place of the ere6l Image behind a Concave 

 Speculum; 2. and of the Image formed by a Concavo-convex Mirror, which is 

 not Left-handed, and has the Property of revolving on its Axis along with the 

 Mirror, but twice as fall; and, 3. the Figure of the Sky. By a Correfpon- 

 dent. -.--_--. 71 



XVII. A New Method of preparing the pure Gallic Acid. 3y M. L. Schnau- 

 bert, * • • • -• * ^ 74 



Scientific 



