xvili CONTENTS. 



hivecxctfsof acid. Cryftjllizcd aUim is a triple fait, and contains a notable proportion ofpotafli, 

 or ammoniac. Analyfis of the slums of commence. General refults of mucli importance to the 

 arts, &c. 



\l\. Defcription of an Inftmment proper to meafure the Volume of a Body, 

 withoui plunging ic in any Liquid. By H. Say, Capitainedu Genie p. 325 



Determination of the bulks of bodies, by imractfion in air inftcad of water or other liquids. Limit* 

 of error in this method. 



Vlil. Ufciul Notices rcfpefting various ObjecfVs. — Styrian Steel — Eiaftic Strings 

 for Mulical Inftruments, and other Purpofcs. Wheels without Cogs p. 328 



Styrian lied is made from any kind of iron. Proccfs. Silk fubftitutcd for catgut. Wheels aAing on 

 each other by the end grain of wood. 



IX. An economical Procefs to obtain pure cauftic Alkali in the large way, 

 with fufed PotaOi, or the Lapis Caufticus. By Citizen Bouillon 

 Le Grange — — — — p. 329 



Apparatus. Depuration of alkali by flaking with lime, percolation of water, and fubfcquent evapo- 

 ration in an iron veffel. Bertholkt's method with alcohol 



X. A Table for reducing the Unities of the Metre, Litre, and Gramme, into 

 Englilh Inches, Gallons, and Grains — — p. 332 



Mathematical and Philofophical Correfpondcnce — — P- 333 



Mr. Varley's fcheme for a perpetual motion. 



Publications on Galvanifm — — ~" P' 333 



NOVEMBER 1797. 



I. Experiments and Obfervations on the Nature of Sugar. By William 

 Cruickfhmk, Chemift to the Ordnance, and Surgeon of Artillery p. 337 



DcftruQive diftilliUion of fugar — and of gum arabic. Pneumatic experiments on malting. Oxygene 

 is abforbed ; and is abfolutely neccflary. Expeiiments for converting fugar into nuicilagt, by 

 abflra£ling oxygene. Unfuccefsful attempts to convert gum into fugar. 



II. An Account of the Manner in which Heat is propagated in Fluids, and its 

 general Confcqucnces in the Economy of the Univeife. By Benjamin Cotmc 

 of Rum ford (Continued from p. 296.) — — - p. 341 



The motion of a fluid while changing its temperature, (hewn in a ftriking manner by floating pieces 

 of amber. The upper part of a fluid may boil without heating the reft. Experiments with ice 

 and water, by which it is fhcwn, that water at 40 degrees will melt as much ice while ftanding on 

 itb furfacc, ai an equal volume of boiling hot water. 



HI.- Experiments and Obfervations made with the View of afcertaining the 

 Natuic of the Gaz produced by pafling eleftric Difcharges through Water; 



with 



