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MINUTES OF PEOCEEDINGS 
OF THE 
EOYAL SOCIETY OF SOUTH AFEICA. 
Oedinary Monthly Meeting. 
March 17, 1909. 
Dr. Wm. Flint in the Chair. 
Messrs. E. W. Davy, W. Jardine and A. E. E, Walker were 
nominated for Ordinary Membership. 
The following communications were read : — 
" The Spectrum of the Euby." A new characteristic test by J. 
MoiR, F.E.G.S. 
On placing a ruby before the slit of a spectroscope, using strong 
illumination, preferably sunlight, a very remarkable absorption-spectrum 
is obtained, which differs from all others in resembling an ordinary 
emission spectrum. The light is cut off except for a sharp narrow red 
band situated just beyond the B line of the solar spectrum, and this band 
bears the closest resemblance to the potassium or lithium line as com- 
monly seen in the Bunsen flame when a rather wide slit is used. The 
limiting wave-lengths of the band are about 6,915 and 6,945 centimetres. 
Its width is therefore about half its distance from the B line in the 
solar spectrum. The phenomenon is most easily seen in pale rubies ; 
corundum with even the faintest pink shade generally shows the cha- 
racteristic line ; but even the darkest true rubies show it if the illumination 
be strong enough. No other pink or red stone — pyrope, almandine, spinel, 
or tourmaline for example — shows this line, which would therefore appear 
to be characteristic of the colouring of the true ruby. In addition to the 
red line the spectrum contains wide green and orange bands which are, 
however, not characteristic. 
" Eemarks on some Experiments with the Venom of South African 
