SCIENTIFIC SUMMARY. 
433 
CHEMISTRY. 
Statue of the late Master of the Mint. — Mr. William Brodie, R.S.A., has 
just completed the full-sized model in clay of a colossal statue, to he erected 
in Glasgow, of the late Thomas Graham, Master of the Mint. Dr. Graham’s 
researches and discoveries in chemistry are known to all scientific inquirers. 
To general readers it may he necessary to mention that Dr. Graham was a 
native of Glasgow, being horn in that city in 1805. At the age of twenty- 
five he became Professor of Chemistry at the Andersonian University ; and 
in 1837 he succeeded Dr. Turner as Chemical Professor in University College, 
London, which position he held till 1855, when he was appointed Master 
of the Mint. In the same year he was created an honorary D.C.L. by the 
University of Oxford; he was also a Fellow of the Royal Society, and a 
Corresponding Member of the Academy of Science of the Institute of 
France. His “Elements of Chemistry” is a standard class-book, and he is 
known also as the author of a number of scientific papers. The memorial 
about to be erected in his native city is due to the gratitude and munifi- 
cence of an old pupil, a wealthy Glasgow gentleman. The statue is to be 
cast in bronze, and is to occupy a position at the south-east corner of George. 
Square, corresponding with that of Chantrey’s celebrated figure of James 
Watt at the south-west corner. 
The compound Ammonium Amalgam formed by the Battery. — In a late 
number of “Silliman’s American Journal,” the late 0. M. Wetherill 
gives an account of the above. He says that a piece of filter paper was 
placed upon a glass plate, then saturated with a strong solution of the re- 
crystallised methyl ammonium oxalate. A globule of mercury of the 
size of a small pea was placed upon the paper, with the negative 
pole of twenty cells Bunsen in contact with it, the positive pole touching 
the paper. The globule swelled slightly, presented a buttery appearance, 
attached itself to and amalgamated the blade of a penknife which was in con- 
tact with the negative pole, and upon being pressed under a glass plate 
showed innumerable gas bubbles in its substance (in fact was a metallic froth), 
which emitted an ammoniacal odour. He promised other papers dealing 
more at length with the subject, but we suppose they were not done before 
his decease. 
Cobalt Ultramarine. — In the “Journal fur Prak Chemie” [Nos. 8, 9], Herr 
W. Stein contributes a paper on this subject. The author first refers briefly 
to his researches on ultramarine (see “ Chemical News,” vol. xxiii. pp. 119, 
142, and 204), reminding his readers that a blue colour may result from the 
intimate mixing of a black and a white molecule. Next this paper contains 
researches on a sample of cobalt ultramarine, which had been kept for some 
twenty years in the museum of the Dresden Polytechnic School. The 
result of the analysis of that substance led to the following composition, in 
300 parts: — Silica, 4-0; alumina, 68*45; cobalt (metal), 20*80; oxygen 
6*75. The composition of the oxide of cobalt present in this ultramarine is 
4CoO.Co 2 0 3 . The analysis was confirmed by the synthesis of an ultramarine 
cobalt — viz. by simply igniting the black oxide of cobalt of commerce with 
alumina. 
