CONTENTS 



OF THE 



FOURTH VOLUME. 



PART I. 

 HIS TORT of the SOCIETr. 



Four Theorems for refolving all the Cafes of Plane and Spheri- 

 cal Triangles, by the Reverend "Mr YiOxtr, - Page 4. 



Dijfertation on the Philofophy of Light, Heat, and Fire, by 

 Dr Hutton, - - - - 7. 



Improvement of the Mercurial Level, by Mr Keith, - 1 7. 



Experiments on the Effe6is of Opium on the Living Animal, by 

 Dr Wilfon, - - - - 18. 



On the Diurnal Variations of the Barometer, by Dr Balfour 

 of Calcutta, - - _ _ 25. 



On the Sulphurating of Metals, by Dr Hutton, - 27. 



New Obfervatory at Aberdeen, - - 29. 



APPENDIX. 



OJjce..Bearers of the Society, - - — 31. 



List o/" Members, continued from the third Volume, - ^2. 



Members deceased, - - - ^6. 



Donations, _ _. - - . 38. 



I. Biographical Account of Lord Ahercvovnby, - (i). 



II. Biographical Account of William Tytler, Efq; of Wood- 



heufelee, ~ - - (17)" 



III. Biogra- 



