CONTENTS. 
1. On a Method of determining Vapour Densities at High Temperatures, and on a 
new form of Quartz Manometer. By G. E. Gibson, B.Sc., Ph.D. (Carnegie 
Fellow, 1912). Communicated by Professor John Gibson. Issued separately 
January 17, 1913, ........ 
2. The Hydroid Zoophytes collected by the British Antarctic Expedition of Sir 
Ernest Shackleton, 1908. By James Ritchie, M.A., D.Sc., Royal Scottish 
Museum, Edinburgh. Communicated by W. Eagle Clarke, F.L.S. Issued 
separately February 13, 1913, 
3. The Absorption of Light by Inorganic Salts. No. VII. : Aqueous Solutions of 
Iron Salts. By John S. Anderson, M.A., B.Sc., 1851 Exhibition Research 
Scholar (Glasgow.) Communicated by Dr R. A. Houstoun. Issued separately 
February 13, 1913, ......... 
4. The Absorption of Light by Inorganic Salts. No. VIII. : Alcoholic Solutions of 
Copper, Cobalt, and Nickel Salts in the Ultra-Violet. By Alex. R. Brown, 
M.A., B.Sc., Carnegie Research Scholar in the University of Glasgow. Com- 
municated by Dr R. A. Houstoun. Issued separately February 13, 1913, 
5. The Theory of Axisymmetric Determinants from 1857 to 1880. By Thomas 
Muir, LL.D. Issued separately March 15, 1913, 
6. The Precipitation of Salts by the Corresponding Acids. By Irvine Masson, 
M.Sc. (1851 Exhibition Scholar of the University of Melbourne). Com- 
municated by Professor James Walker, F.R.S. Issued separately March 
24, 1913, . . . . . . . . 
7. Preliminary Observations on Magnetic Induction in Ferric Oxide at Various 
Temperatures and in Different States, and on the Possible Chemical Changes 
indicated by the Observations. By G. E. Allan, D.Sc., Lecturer on Electricity, 
Pure and Applied, and Assistant to the Professor of Natural Philosophy in 
the University of Glasgow ; and John Brown, M.A., B.Sc., Houldsworth 
Research Scholar in the University of Glasgow. Communicated by Professor 
A. Gray, F.R.S. Issued separately March 24, 1913, 
8. Studies on Periodicity in Plant Growth. Part I. : A Four-Day Periodicity and 
Root Periodicity. By R. A. Robertson, M.A., F.L.S., and Rosalind Crosse, 
B. Sc., Carnegie Research Scholar, Botanical Department, The University, 
St Andrews. (With Three Plates.) Issued separately March 26, 1913, 
9. The Error caused by “ Lag ” in a Recording Instrument : An Experimental 
Study. By J. R. Milne, D.Sc., and H. Levy, M.A., B.Sc.; Carnegie Scholar. 
Issued separately April 11, 1913, 
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