PROCEEDINGS 
OF THE 
ROYAL SOCIETY OF EDINBURGH. 
' 
Vol. XVIII. 
SESSION 1 8 90-9 1. 
CONTENTS. 
■ _ - 
Election of Office-Bearers at the General Statutory Meeting, Monday, Nov. 24, 
1890, . . 
Chairman’s Opening Address, ....... 
On the Occurrence of Sulphur in Marine Muds and Nodules, and its bearing on 
their Mode of Formation. By J. Y. Buchanan, F.R.S., 
On a Simple Pocket Dust-Counter. By John Aitken, F.R.S. (With a Plate), 
On the Action of Metallic (and other) Salts on Carbonate of Lime. By Robert 
Irvine, F.C.S., and W. S. Anderson, 
Manganese Deposits in Marine Muds. By Robert Irvine, F.C.S., and John 
Gibson, Ph.D., . . . . . . . 
On a Difference between the Diurnal Barometric Curves at Greenwich and at 
Kew. By Alexander Buchan, LL.D., . . . . 
Barographic Record in the Vicinity of a Tornado. By John Anderson. Com- 
municated by Dr Buchan. (With a Plate), . 
Note on Potassium Persulphate. By Hugh Marshall, D.Sc., . 
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