SOUTH AFRICAN JOURNAL 

 OF SCIENCE : 



COMPRISING THE REPORT OF THE 



SOUTH AFRICAN ASSOCIATION 



FOR THE 



ADVANCEMENT OF SCIENCE 



1922 



LOURENCO MARQUES. 



OFFICERS, 1922-1923. 



PRESIDENT. 

 Prof. J. D. F. Gilchrist, M.A., D.Sc, Ph.D. 



VICE-PRESIDENTS. 



S. G. Campbell, M.D., M.Ch. 



J. A. FooTE, F.G.S. Prof. T. M. Forsyth, M.A., Ph.D. 



C. W. Mally, M.Sc. 



HON. GENERAL SECRETARIES. 



H. E. Wood, M.Sc, F.R.A.S., Union Observatory, Johannesburg. 

 C. F. JuRiTZ, M.A., D.Sc, F.I.C., Division of Chemistry, Dept. of Agriculture,. 



Capetown. 



HON. GENERAL TREASURER. 

 Jas. Gray, F.I.C, Johannesburg. 



HON. LIBRARIAN. 



Annie Porter, D.Sc, South African Institute for Medical Research, Johannesburg, 



ASSISTANT GENERAL SECRETARY. 

 H. A. G. Jeffreys, O.B.E., Box 6894, Johannesburg. Tel. Address: "Science." 



HON. EDITOR OF JOURNAL. 

 Prof. H. B. Fantham, M.A., D.Sc, The University, Johannesburg. 



VOL. XIX DECEMBER. 1922. VOL. XIX 



JOHANNESBURG. 

 PUBLISHED BY THE ASSOCIATION. 



1922. 



[PRICE 30s. oet. 



