200 R. Mallet-—Mechanism of Stromboli. 
0°6405 gr. fused with potassio-sodic carbonate gave 0°5564 gr. 
silver=28°55 per cent chlorine, 071986 gr. platinum=31-00 per 
cent, and 0°0597 gr. cobalt=9°33 per cent. 
The platinum and cobalt were weighed together as metals 
after reduction by hydrogen, and the cobalt was then dissolved 
by long boiling with nitric acid. 
This formula, Co,(N Hg)io(NO)o(NO3).C],4 2PtCl,, requires 
ound, 
Cobalt 9°40 9°33 
Platinum 31°55 31°00 
Chlorine 28°28 28°55 
The salt had no water on heating to 140° C. 
(To be continued.) 
Art. XIX.—On the Mechanism of Stromboli; by RoBERT 
MALLET, M.A., F.R.S. 
[Abstract of a paper received by the Royal Society of London, May 17, 1874, and 
read June 25, 1874] 
STROMBOLI stands unique (omitting the as yet imperfectly 
known Masaya in Central America), amongst the volcanoes of © 
our globe as characterized by the rhythmical recurrence of its 
outbursts, which have continued with but little alteration for 
more than 2000 years. The phenomena of Stromboli have 
been more or less accurately described by several authors, from 
Spallanzani and Hoffman to Scrope and Daubenay. The last 
but one of these has proposed an explanation of the phenomena 
presented by the recurrent outbursts at short intervals of time, 
which within rather narrow limits are constant, and in the tradi- 
tional convictions are supposed to have some connection with 
ao the geysers of Iceland; to some of the circumstances, 
_ those experimentally — i 
