CONTENTS. 



OCTOBER 1797. 



I; An Account of the Manner in which Heat is propagated in Fkiids, and its 

 general Confeqiiences in the Economy of the Univerfe. By Benjamin 

 Count of Rumford — — — p. 289 



General view of the theory of heat. Equilibrium of temperature' — Capacities — in the ftites of 

 fo'.idity, fluidity, and clalticity — altered by cliinge of combination. Coiiduftiiig powers. Fluids 

 affirmed to be non-conduilors. — Inftances: wiili large tliermom;ters — with an apparatus contrivtrd 

 for the fame purpole. Conduclin^j power of fluids impaired by mixture of fibrous or glutinous 

 matter. Clothing is more effeiftual for prcferving the temperature of bodies in water, than evca 

 in air. General applicati^Dn of the experimentsto the power which animuls and vegetables poflcl's, 

 of preferving their temperature. 



II. Experiments and Obfervations on the fulminating Preparations of Gold 

 and Silver — — — — p. 296 



Fulminating gold— Silver — Procefs. G,-«t danger from this experiment, with ftrong folution of 

 ammoniac. Prince Rupert's drop. Danger of the powder of oxygenated muriate of potadi and 

 fulphur, from fpontaneous cxplofion. 



III. Experiments and Obfervations ma'le with the View of afcertainino- the 

 Nature of the Ga?. produced by palTiug eleAric Ddcharges through VVater, 

 with a Difcription of the A;i[iararus for thefe Experiments. By George 

 Pearfon, M.D. F.R.S. (Continued fiom p. 248.) P- 200 



D:compofuion of water by interrupted difcharges — and by complete difcharges. Mode of action. ■ 



IV. Experimental Rcfcarches to afcertain the Nature of the Procefs by which 

 the Eye adapts itfeif to produce diftincl Vifion — p. ,05 



Mr. Young's obfervations on t'u; mufcularity of the cornea. Mr. John Hunter's difcovery of the 

 fame fibrous flruflure. Dr. Ho.Tack's i.ivclligatiun of the effeA of the external mufcles of the eye. 

 Mr. Home's lefture on the eye. Mr. Ramfden's obfervations, tending to ftiew the true parpofe 

 anfwered by the ftrudure of the crvftalline. Very ilriking inllance of adjuilment in the eye, after 

 extraction of ihe cryftjihne. Experiments to fhew, Uiat the aftion of the (Irait mufcles ca'ufes a 

 variation in the cornea, at the inliint of adjullment, and of the fame kind as that adjudment de- 

 mands. Recapitulation. 



V. Concerning the Properties of the Sulphureous Acid, and its Combinations 

 with Eirthy and Alkaline Bafes. By Citizens Fourcroy and Vauquelin p. " 1 3 



Phyfical properties of the acid — chemical properties with caloric ; oxygene ; water ; otiier acija ■ 

 combuftibie bodies; alkalis. ' 



VI. A Memoir on the Nature of the Alum of Commerce, on the Exigence of 

 Potadi ':i this Salt, and on various limple or triple Combinations of AJuminc 

 with the Sulphuric Acid. Read before the National Inftitute of France. 

 By Citizen Vuuqtielin — — — — p. ?i8 



Theory of the effcit of alkalis in alum-making, requires elucidation. Pure fulphate of ahimine does 



not eryftallizc. It cryltalMzes by the addition of a few drops of folution of potadi; but not bv 



carbonate of foda; nor lime; nor barytes. The addition of potafli, or ammoniac, do.-3 not fcrve 

 to faturate an cwefs of acid : their fulphates anfwcr the fame purpofe, even though they may 



luvc 



