476 | Scientific Intelligence. 
the northern slope of Epomeo; and that the cause of the in- 
creased tension resulting in this rupture is to be referred to 
the residual voleanic activity which this island shares with the 
adjacent mainland rather than to any merely local subsidence. 
Palmieri has advanced the opinion that the local violence of 
the shocks might be due to the collapse of subterranean cavi- 
ties not very far below the surface. But it would seem likely. 
that any subsidence of sufficient magnitude to cause the surface 
destruction, seen at Casamicciola, and to give rise to vibrations 
felt by instruments so far away as Rome, must have been 
attended also by surface fissures and changes of level, none of 
which were observed. 
After the disastrous earthquake of July 28, slight shocks 
continued to occur, at first daily, and afterward at longer inter- 
vals, even as late as September 23d. 
In preparing this notice free use has been made of the corre- 
spondence published in various journals and newspapers both . 
of America and Europe, but the writer is especially indebted to 
articles contributed by Ch. Vélain to La Nature (August 18, 
1888); by H. J. Jobnston-Lavis to Nature (Sept. 6, 1883), and 
by L. Baldacci to the Boll. R. Com. Geol. (translated in 
Science, Sept. 21, 1883.) 
SCIENTIFIC. IN TELLIGEROS: 
I. CHEMISTRY AND PuysIcs. 
The | 
selenium is immediately covered with a thin plate of glass called 
tint. Seen through the spectroscope, the light is comprised be- 
tween the A line and the C line. The double line B and the nu 
merous small lines @ are readily seen, but the D lines can not 
observed. ere is, so to speak, 
radiation of the sodium lines. 
