ir CONTENT S, 



AUGUST, 1 80^. 



Engravings of the following Objefls : 1. An Apparatus communicated by Count 

 Rumford, for iliuftrating his Experirnents in Proof that the greateft Denfity of 

 Water is higher than the freezing Point ; 2 A Valve for Steam Engines, 

 ^Arhich opens either inwards or outwai'ds by PrelTures feparately adjuftibie, by 

 the Chevalier Edelcrantz ; 3. Figures and Diagrams by Edward Pigott, Efq. - 

 to illuftrate the Caules of periodical Increafe and Diminution of Light in a Star 

 in Sobicflci's Shield ; 4. A Prefs for Botanical Specimens, by Mr. Harrifon, 



I. An Account of fome new Experiments, which prove that the Temper- 

 ature at which the Denfity of Water is a Maximum, is feveral Degrees of 

 the Thermometer above the freezing. Point. By Benjamin Count of Rum- 

 ford, V, P. R. S. Foreign Aflbciate of the National Inftitute of France, 

 ice. &c. Received July 16, 1805, from the Author; with a Letter dated 

 ' Munich, 2ath June, ISOj. - . - • - - Page 225 



H. Delcription of a Prefs for preferving botanical Subjects j with an Accojint^ 

 of the Succefs of the Improvement in the Art of Blafting pointed out by Mr. 

 Jeflbp in this Journal. Ih a Lett^ from Mr. The. Harrjibn. 23S 



in. Defcription of a Safety Valve, containing a Vacuum Valve in the fame 

 Hole of the Boiler. By Sir A. Ni Edelcrantz. - - 243 



IV. Obfervations and Experiments for the Purpofe of afcertalning the definite 

 Chara6lers of the primary Animal Fluids, and to indicate their Prefencc 

 by accurate chemical Tefts. By John Bollock, M. D. Communicated by. 

 the Author. - - - • . 244, 



V. On mufcular Motion. By Anthony Carlifle, Efq. F. R. S^ being the 

 Croonian Lefture, read before tke Royal Society, Nov. 8, 1804. 255 



VL On the Meafure of mechanic Power. In a Letter from Mr. J. C. Horn- 

 blower. - - - - - - 264' 



VJL An InveftigrUion of aH the Changes of the variable Star in Sobiefki's Shield, 

 from five Years Obfervations; exhibiting its proportional illuminated Parts, 

 and its Irregularities of Rotation ; with Conje6lures refpe6ling unenlightened 

 heavenly Bodies. By Edward Pigott, Efq. Abridged from the Phil, Tranf. 

 for 1805. - - - - - - 271 



VIII. Account of a luminous Meteor. By a Conftant Reader. 281 



IX. Precipitation of Platina as a Covering or Defence to poliflied Steel, and 

 alfo to Brafs. In a Letter from Mr, J. Stodart. - • 282 



X. Experiments on Wootz. By Mr. David Mufhett. From the Phllofo- 

 phical Tranfu^lions, 1805. - - - - 284^ 



XI. A Memoir on the Webs of Spiders. By C. L. Cadet. - - 290 



XII. Information on the Mines and Manufa6lures of the Eaft Indies, and 

 other Subjeas, By J. Machlachlan, Efq. of Calcutta. - 294 



Scientific News, 299. — Imperial Academy of Sciences at Peterfburgh, ib. — 

 Prize concerning Lighr, propofed by the Imperial Academy of Sciences for 

 the Year I8Q6, 300. — Voyages of MelTrs. Humboldt and Bonpland, 301.— 

 Fifli ejefted from Volcanoes, 303. — Water formed by mechanical Preffureli ib» 

 Malleability of Zinc, 301.— Palladium, ib. 



