240 
PROCEEDINGS OF SECTION B. 
My reason for making these experiments is that Mr. H. C. 
Russell, C.M.G., F.R.S., the Government Astronomer, some years ago 
tried aluminium cups for a rain-gauge, but found that they were so 
quickly corroded through that he had to relinquish the use of the 
metal. Lf they had been gilt they might, however, have answered well 
enough. Then, too, it is a very common thing to see aluminium 
recommended for certain architectural work on account of its light- 
ness and its assumed permanent lustre, this assumption being due to 
the statements, repeated from book to book, that aluminium is 
unaltered by exposure to the air, that it is unacted upon by water, 
hydrogen sulphide, and only slightly by dilute acids — even in modem 
special treatises such as “ Aluminium,’ 5 by Joseph W. Richards, M.A., 
London, 1890. 
The absolutely pure metal may be permanent in the air, but the 
best aluminium ordinarily obtainable is in that respect very little, if at 
all, superior to zinc. 
Recently it has been found that sea- water acts upon aluminium 
with some quickness, hence it is not so perfect a material for torpedo 
and other boats as was previously thought. 
Hence the prevalent idea that aluminium is a metal resembling 
gold or silver in the property of not oxidising must be relinquished. 
3.— CRYSTALLISED CARBON DIOXIDE. 
By A. LIVERSIDGE , M.A., F.R.S., Professor of Chemistry , University of 
Sydney , N. S. W. 
When solid carbon-dioxide is examined under the microscope it 
presents along its edges projecting wir'e-like crystals, which have 
branching filaments issuing from them, apparently at right angles, 
resembling somewhat the groups of minute crystals seen in crystallised 
iron, gold, and ammonium chloride. 
The rapidity with which the carbon-dioxide evaporates makes it 
difficult to catch the form of the crystals, either by photography or 
other means. 
4— ON THE INTERNAL STRUCTURE OF GOLD NUGGETS. 
By A. LIVERSIDGE , M.A., F.R.S . , Professor of Chemistry , University of Sydney 9 
N.S.W . 
5.— CONTRIBUTIONS TO THE BIBLIOGRAPHY OF GOLD. 
By A. LIVERSIDGE , M.A., F.R.S., Professor of Chemistry , University of Sydney. 
The following pages contain the titles of various books and papers 
upon the subject of gold which I have recorded in the course of my 
work upon the origin of gold nuggets, Ac., and which are not contained 
in the Bibliography of Gold published in Locke’s Gold (London, 1882) : — 
Aaron, C. H. Leaching Gold and Silver Ores. San Francisco, 1881. 
— Assaying, in three parts. San Francisco, 1884-5. 
