NOTES. L57 
stituent of the mineral tourmaline and axinite, both of 
which are frequently present in the deposits, while the 
most commonly associated elements are tungsten, molyb- 
denum, phosphorus, arsenic, and iron. He arrives, there- 
fore, at the conclusion that tin ore, fluorine compounds, 
and borosilicates owe their origin to the same set of 
reactions, and supposes that the tin, tungsten, molybdenum, 
boron, phosphorus, and a portion of the silicon came up 
through fissures from some deep-seated source of fluorides. 
Finally, he suggests that the present condition of stockwerks, 
which consist of quartz, tin ore, silicates, fluorsilicates, and 
borosilicates, have resulted from the action of these fluorides, 
probably in the presence of water, on the enclosing rocks. 
EXE ISCES: 
Mr. H. Tryon exhibited Alunzte, from Bulladelah, New 
South Wales. Mr. E. B. Lindon alluded to the process by 
which alum was obtained from this mineral, and its com- 
position as compared with other alum minerals. 
Mr. H. Tryonvalso exhibited the egg of a common black 
hen, which had weighed 5} ounces, and which measured 3.4 
inches by 2.2 inches. This egg included a second egg, 
measuring 2.5 inches by 1.5 inches. The shell of each egg 
was well developed, and in both were food-yolks and.albu- 
minous matter in normal proportions. Mr. Tryon alluded 
to the short time prior to their being laid when these eggs 
must have come into their relative positions, and how this 
had been effected. This double egg had been forwarded to 
the Queensland Museum by Mr. Price Fletcher, of Brisbane. 
Mr. J. Thorpe exhibited a barograph-tracing for the 
month of November, and drew attention to the chief 
incidents which it illustrated. He also commented on the 
invariable influence on these tracings of the passage of an 
area of low barometric pressure across the South of Aus- 
tralia, from W. to E. 
Mr. J. Falconer, C.E., exhibited different auriferous rocks 
of secondary origin, as cements and gossams, derived from 
ores which had been worked for copper. He also dwelt at 
