514 Proceedings of Royal Society of Edinhurgh. [sess. 
Monday, 2nd July 1894. 
The Hon. Lord McLaren, Vice-President, in the Chair. 
The following Communications were read : — 
1. Co-ordinates versus Quaternions. By Professor Cayley. P. xx. 
271. 
2. On the Intrinsic Nature of the Quaternion Method. By Professor 
Tait. P. XX. 276. 
3. Note on the Volume Changes which accompany Magnetization in 
Nickel Tubes. By Dr C. G. Knott and A. Shand, Esq. P. xx. 295. 
4. On Histological Changes produced in Nerve Cells by their Func- 
tional Activity. By Gustav Mann, M.B. Communicated by Professor 
Rutherford. 
The following Candidates for Fellowship were balloted for, and 
declared duly elected Fellows of the Society : — 
Robert Mackenzie, M.D. 
William Shield, M.Inst.C.E. 
Philip R. D. Maclagan. 
Tuesday, \0th July 1894. 
The Hon. Lord McLaren, Vice-President, in the Chair. 
The following Communications were read : — 
1. On the Measurement of the Simple Reaction Time of Hearing, 
Sight, and Touch. (With Experimental Illustrations.) By Professor 
Rutherford, F.R.S. P. xx. 328. 
2. The Estimated Total Amounts of the Principal Substances in 
Solution in the Ocean, and the Source of these Substances. By Dr 
John Murray. 
Monday, \Mh Jidy 1894. 
Professor Chrystal, Vice-President, in the Chair. 
The following Communications were read : — 
1. On the Circulation of Water in the Faero-Shetland Channel and 
the North Sea. By Mr H. N. Dickson. 
2. Note on the Compressibility of the Water of the Great Salt Lake, 
Utah. By Professor Tait. 
3. On the Solution of Systems of Equations by means of Deter- 
minants. By the Hon. Lord McLaren. 
4. Preliminary Note on the Use of Phosgene in preparing Compound 
Ethers. By Professor Crum Brown. 
5. On the Fossil Fishes of Forfarshire. By Dr R. H. Traquair, 
F.R.S. 
6. The Chairman reviewed the work of the Session. 
