ABSTRACT OF PROCEEEINGS. 
XI. 
Abstract of Proceedings, 27th September, 1943. 
The Ordinary Monthly Meeting of the Society was held in the Sir 
William Macgregor School of Physiology on Monday, 27th September, 
at 8 p.m., with the President (Prof. J. Bostoek) in the chair. About 
forty members and friends were present. The minutes of the previous 
meeting were read and confirmed. Mr. Erskine, Mr. J. E. Cary and 
Mr. L. McGrath were elected to Ordinary Membership, and Mr. H. V. 
Brown was proposed for Ordinary Membership. 
Prof. D. H. K. Lee demonstrated an apparatus — Efficiency Tester : 
Gunlaying type — designed and constructed in the Physiology Depart- 
ment with the assistance of G. Klemm. This records the speed with 
which a test subject can successfully lay a telescopic sight on a target 
or series of targets. The lighting-up of the selected target and the 
successful laying of the sight are recorded independently on a rotating 
drum, from which the time interval can be calculated. 
Mr. C. T. White exhibited specimens of three species of Duboisia. 
Mr. F. A. Perkins exhibited a specimen of Ascaris ( Pienis rapce ), 
Cabbage Butterfly, which was caught by Mr. E. J. Dumigan at 
Toowoomba on the 14th March, 1943. This is the first record of this 
serious pest occurring in Queensland. No doubt, as in other countries, 
it will spread very rapidly and will continue to be a major pest of 
'Cruciferous plants. 
Mr. I. R. Bick demonstrated the phenomenon of rotary dispersion 
of polarised light on passing through a sugar solution. A polaroid 
disc was used to polarise the light. 
Mr. J. Leeming Schofield exhibited a specimen of Rotenone pre- 
pared by the Agricultural Chemist’s Section of the Department of 
Agriculture and Stock, obtained from roots of Derris elliptica' var. 
Sarawak creeping, grown at the Bureau of Tropical Agriculture. He 
referred briefly to its special insecticidal properties and to chemical, 
agricultural, and marketing aspects of Derris root production. Refer : 
ence was made to the classical selection work on Derris in Malaya 
carried out by Georgi. 
Mr. D. Metcalfe demonstrated the use of the Industrial X-ray in 
the production of a sound steel casting. 
Dr. W. H. Bryan exhibited a series of specimens illustrating 
colour in minerals. He pointed out that whereas some minerals have 
their peculiar and characteristic colours, many others display a wide 
range of colour. Some of the most striking colour effects were shown 
to be due to the presence of chemical impurities or physical 
imperfections. 
