CONTENTS. tR 



Whenever water is frozen and again thawed, there is an extindlion or produdlion of azote, which 

 is alike in quantity at each fucceilive procefs.- Remarks and obfervations. 



II. On the Abforbent Powers of different Earths. By Mr. John Leflie. p. 196 



III. On a New Fuhninating Mercury. By Edward Howard, Efq. F. R. S. 

 (Continaed from p. 178.) - - - - p. 200 



IV. Account of a Scries of Experiments, undertaken with the View of decom- 

 pofing the Muriatic Acid. By Mr. William Henry. - p. 209 



V. Eudiometric Obfervations. By Citizen Berthollet. - p. 214 



VI. Analyfis of a new Variety of Lead Ore. By Richard Chevenix, Efq. 



p. 219 



V\\. Experiments on the Chemical Effects of Galvanic Ele£tricity. By Mr. 

 William Henry. - - - . , . - P- 223 



The Galvanic current afls niofl firongly on water through pointed metal. — Decompofition of con- 

 centrated fulphuric acid ; — of nitric acid ; — of the oxigenated, hut not the common, muriatic 

 acid. Attempt to fubje6l the gafes to the Galvanic energy. Remarkable fadls in the decom- 

 pofition of the alcalis. 



VIII. Defcription of a new Inftrument for repeating the Examination of the 

 Strata which have been penetrated by the common boring Inftrument ufed in 

 Mine Works. By A. Baillet, Infpeftor of Mines, and Profeflbr at the 

 Mineral School at Paris. - - - . - p. 227 



A cylindrical piece carries two knives, which are forced outwards at any depth, in a hole already 

 bored. Thefe cut off a portion of the ground, which is brought up for examination. 



IX. General Principles and Conftruftion of a Sub-marine Veffel^ communi- 

 cated by D. Buflmell, of Connefticut, the Inventor, in a Letter of Oftober, 

 1787, to Thomas JcfFerfon, then Minifter Plenipotentiary of the United 

 States at Paris. - ■ - - - - " P- 229 



X. Queftion refpefting the Purification of Copper for alloying Gold. By X. Y. 



p. 235 



XI. On the Art of Hat making. Supplementary Letter. By N. L. p. 236 



XII. On the Inventbns of Robert Hooke, for regulating Time Pieces. By a 

 Correfpondent. - - - - p. 237 



Scientific Publications. - ' , - - - p. 239, 240. 



Philofophical Tranfa6tions of the Royal Society of London for the year 1800. Parti. — Refcarches, 

 Chemical and Philofophical, concerning Nitrous Oxide, or Dephlogiflicaled Nitrous Air, and 

 its Refpiration. — The Dodrine of Phlogifton eflablifhed, and that of the Compofition of Water 

 refuted. — Tranfaftions of the Royal Sofciety of Edinburgh. Vol. V. Part I. for 1799. 



S SEPTEMBER 



