1901 - 2 .] 
Meetings of the Society. 
589 
2. Amorphous Sulphur and its relation to the Freezing-Point of Liquid 
Sulphur. By Professor Alexander Smith, Ph.D., B.Sc. pp. 299-301. 
3. On the Use of the Quaternions in the Theory of Screws, etc. By 
Wm. Peddie, Esq., D.Sc. pp. 314-320. 
4. Dissociation of the Compound of Iodine and Thio-urea. By Hugh 
Marshall, Esq., D.Sc. pp. 233-239. 
Dr Robert Stevenson Thomson and Mr Charles T. R. 
Wilson, M.A., F.R.S., were balloted for, and declared duly 
elected Fellows of the Society. 
FOURTEENTH ORDINARY MEETING. 
Monday , 1 6th June 1902. 
The Hon. Lord MDaren, LL.D., Vice-President, in the Chair. 
Dr Charles Du Riche Preller was admitted a Fellow of the 
Society. 
The following Communications were read : — 
1. Quaternion Notes. By the late Professor Tait. Communicated by 
Dr Knott, pp. 344-346. 
2. Volcanic Dust from the Recent Eruption on the 8th May 1902, at 
St Pierre, Martinique. By Professor Andrew Jamieson. A specimen 
was exhibited under the microscope. 
3. Change of Resistance of Nickel due to Magnetisation at Various 
Temperatures. By C. G. Knott, Esq., D.Sc. Trans., vol. 40, pp. 535- 
545. 
4. Thallic Sulphates and Double Sulphates. By Hugh Marshall, 
Esq. pp. 305-311. 
FIFTEENTH ORDINARY MEETING. 
Monday , 7th July 1902. 
Sir Wm. Turner, K.C.B., Vice-President, in the Chair. 
Mr Charles T. R. Wilson was admitted a Fellow of the Society. 
The following Communications were read : — 
1. Obituary Notice of Lieut.-Colonel J. H. B. Hallen, C.I.E., F.R.C.S.E. 
By Principal W. Owen Williams, pp. 642-645. 
2. Contributions to Scottish Mineralogy. Part I. By J. G. Goodchild, 
