CONTENTS. iii 



MARCH 1 802. 



Engravings of the following Objects : 1. Anew and powerful Engine, which 

 acts by the alternate or double PrefTure of a Column of Water on each Side 

 of a Pifton. By Mr. R. Trevithack. a. Dr. Murray's Apparatus for new 

 Experiments on the Tranfmiflion of Heat through Fluids. 3. Dr. Herfchell's 

 darkening Apparatus to view the Sun through Fluids. And, 4. Hydraulic 

 Bellows tor a Smith's Forge. By Mr. Hornblower. 



J. Defcription of an Engine which operates by the Preffure and Defcent of a 

 Column of Water againft a Pifton $ nearly in the fame Manner as the double 

 Steam Engine operates by Means of Steam. Communicated by the Inventor 

 Mr. Richard Trevithack, of Camborne, near Truro, in Cornwall Page 161 



II. Experiments and Remarks on the PafTage of Heat through Fluids down- 

 wards, particularly with Regard to the Uncertainty produced by the VefTel j 

 with a Method of obviating that Uncertainty altogether. By John Murray, 

 M. D. Lectnrer on Natural Philofophy and Chemiftry at Edinburgh. Com- 

 municated by the Author . - - - - 165 



III. Letter from Dr. Van Marum to Mr. Volta, Profeflor at Pavia, containing 

 Experiments on the Electric Pile, made by him and Profeflor Pfaff, in the 

 Teylerian Laboratory at Haarlem, in November, 1801 • 173 



IV. A Reply to Mr. Cruick/hank's Obfervations in Defence of the New Syftem: 

 of Chemiftry, in the Philofophical Journal. By Jofeph Prieftley, L. L. D. 

 F. R. S. &c. Communicated by the Author - - 181 



V. A Statement of the Experiments made, by the Rev. Abraham Bennet, F.R.S. 

 on the Electricity produced by the contact of Metals previous to the Year 

 1789, and alfo of thofe made by Mr. Tiberius Cavallo, F. R. S. previous 

 to the Year 1795, to which Allufion was made at Page 144 of this Journal. 

 —W.N. - - - - ' 184 



VI. On the Formation of Cryftals, defcribing a Method of producing them 

 large and regular. By Cit. Le Blanc - - - 191 



VII. Accounts of the New Planet Ceres . >- - 193 



VIII. Obfervations ana Experiments relating to the Pile of Volta. In a Letter 

 from Jofeph Prieftley, L. L. D. F. R. S. - - - 193 



IX. Experiments and Obfervations towards determining the Influence of Oxigen 

 on Germination. By Dr. Carradori ... 204 



X. On the Choice and Ufe of a Razor. By a Correfpondent 210 



XI. Obfervations on the Method cf painting with Milk. By Cit. Darcet, 

 Member of the Lyceum of Arts, and EfTayer of Money - 212 



XII. Defcription of an Hydraulic Bellows for a Smith's Forge. By Mr. J. C. 

 Hornblower - - - 219 



XIII. On the Practicability and Advantage of a general Syftem of Rail-Roads, 

 and the Means of carrying the fame into Effect. In a Letter from Richard 

 Lovell Edgeworth, Efq. ----- 212 



XIV. Defcription of the darkening Apparatus for Telefcopes by Means of 

 Fluids. By William Herfchel, L. L. D. F. R. $. - - 217 



XV. On the Effects of the Refpiration of the Nitrous Oxide j particularly an 

 Inftance in which the Excitation of the Syftem produced unpleafant Symp- 

 toms. In a Letter from Mr. James Stodart - - 225 



XVI. Remarks on the Procefles for clarifying Liquids. By Cit. Parmentier 228 

 Scientific News. Extract of a Letter fromBrunn, in Moravia — On the Muria- 

 tic Aid— A new Method of obtaining the Gallic Acid pure— Extracts of a 

 Letter of Cit. Vauquelin to Cit. Van Mens - 234 to 233 



Account cf Books of Science. Murray's Elements of Chemiftry — Young's 

 Syllabus of a Courfe of Lectures on Natural, and Experimental Philofophy — 

 Mr. B J air's Popular Leaures .... 239, 249 



APRIL 



