CONTENTS. ^^^ 



PAGE 



XVII. Observations on the Principle of Vital Afinity, as illustrated by recent 

 discoveries in Organic Chemistry. By William Pulteney Ali- 

 son M.D., r.R.S.E., Professor of the Practice of Medicine in tlie 

 University of Edinburgh, 165 



XVIII. Account of some Experiments on the Temperature of the Earth at dif- 

 ferent Depths, and in different Soils, near Edinburgh. (With Four 

 Plates.) By James D. Forbes, Esq., F.R.S., Sec. R.S. Ed., &c. 

 Corresponding Member of the Institute of France, and Professor 

 of Natural Philosophy in the University of Edinburgh, . . 189 



PART III. 



XIX. On a Formula representhig the Mean Height of the Barometer at the 

 Level of the Sea. By Professor Hansteen of Christiana, in a 

 Letter addressed to Professor Forbes, Secretary of the Royal 

 Society of Edinburgh, 237 



XX. On General Diferentiatim. Part III. By The Rev. P. Kelland, 

 M.A., F.R.SS. L. & E., F.C.P.S.,late Fellow of Queen's College, 

 Cambridge, Professor of Mathematics, &c., in the University of 

 Edinburgh, 241 



XXI. Observations on the Principle of Vital Affinity, as illustrated by re- 

 cent discoveries in Organic Chemistry. By William Pulteney 

 Alison, M.D., F.Pv.S.E., Professor of the Practice of Medicine in 

 the University of Edinburgh. Part II. .... 305 



XXII. An Attempt to Elucidate and Apply the Principles of Goniometry, as 

 published by Mr Warren, in his Treatise on the Square Roots of 

 Negative Quantities. By The Right Rev. Bishop Terrot, . 345 



XXIII. On the Reaction of Natural Waters with Soluble Lead Salts. By 



Arthur Connell, Esq., F.R.S.E., Professor of Chemistry in the 

 University of St Andrews, ....... 357 



XXIV. On certain Products of Decomposition of the Fioced Oils in contact with 



Sulphur. By Thomas Anderson, Esq., M.D., F.R.S.E., Lecturer 



on Chemistry, Edinburgh, ....... 363 



