. 
SCIENCE AND INDUSTRY. 
Adams and Kohlschiitter found that the relative intensity of selected lines 
in the spectrum of a star depended on the absolute magnitude, and hence were 
led to a method of determining the absolute magnitude from measurements on 
the spectrum. JM being determined, the equation gives 7, and thus the parallax 
can be measured spectroscopically. This work brought out very clearly the 
division of the red stars into a very bright group and a very faint group, with 
no stars of intermediate brightness. 
The absolute magnitude depends on mass, density, and surface brightness. 
The only information as to mass is obtained from binary stars, and for these 
the total range in mass is only from 19 times that of the Sun to ¢ that 
of the Sun. The surface brightness for stars with similar spectra must be 
nearly equal, and thus the average red star of the bright group, which gives out 
1,000 times as much light as the average red star of the faint group, must hayes 
1,000 times the surface and 30,000 times the volume of the latter. Hence the. 
terms giant and dwarf. If the masses are equal, the densities will be in the 
ratio 30,000 to 1. 
For special classes of stars the relative surface brightness can be obtained, 
and it is found that the very white stars give out 500 times as much light per 
unit surface as the very red stars. For the giant stars the density increases 
from the red stars to the white, while for the dwarf stars the density increases _ 
from the white stars to the red. As the giant stars contract and get hotter, the 
increase in surface brightness nearly balances the decrease in surface, and the 
stars remain nearly constant in brightness, as is actually found to be the ease, 
After a limiting density is reached, cooling follows further contraction, and 
both surface brightness and surface decrease together, and a rapid diminution 
of light is the result. This also is confirmed by observation. 
| ROYAL SOCIETY OF SOUTH AUSTRALIA. 
The Society met on 11th November, 1920, Sir Joseph C. Verco, M.D., F.R.C.S, 
(President), in the chair. 
The Hon. Secretary reported that certain old documents referring to the 
origin and early history of the Society had been handed for safe custody to 
the Archives Department of the Public Library, where they would be catalogued, 
and be available at any time for reference. - : 
It was resolved that the Society indorses the following two resolutions passed 
by the Section of Public Health and State Medicine of Australasian Medical 
Congress, held this year in Brisbane, viz.:— 
“§. That this Congress is of opinion that the time has arrived when a ‘ 
campaign of Preventive Medicine should be made real-and effective, and that 
with the object of carrying out such an undertaking, and of fully utilizing 
existing agencies, the Commonwealth Government he ‘approached and 
_ requested to appoint a Royal Commission to fully consider and report. 
That the personnel of such a Commission should contain a considerable 
percentage of unofficial medical practitioners representing various medical 
activities, and also representatives of local governing bodies.” 
“9. That the Congress recognises the importance of preventing the extine- 
tion of wild life in Australia, both on grounds of scientific interest and of 
public health. It urges on the various States Governments the desirability 
of making reservations, biological areas in which the protection of the 
remarkable Australian animals may be adequate.” : 
In this connexion, it was pointed out that, after a campaign which lasted for 
thirteen years, this Society had succeeded in obtaining the passage through 
Parliament of the Flinders Chase Act, establishing such a reserve in the western 
portion of Kangaroo Island, under the control of a Board on which this Society 
and the University of Adelaide: were represented, : 
The President reported that the Council had made to Mr..F. R. Marston a 
grant in aid of research into the possibility of obtaining from azine precipitates 
samples of the pure proteolytic enzimes. 
Numerous exhibits were tabled by fellows, including an aboriginal skeleton, 
showing mended fractures of thigh and arm, recently ploughed up on the land 
of Captain S. A. White, at Fulham, near Adelaide. ; 
700 
