134 Mr. Sturgeon’s Description of the 
14. The crystallized hydrate of chlorine was then put in the 
tube G, fig. 1: it proved a nonconductor. A strong solution 
of chlorine, placed in the same situation, was a good conductor. 
From these experiments the following conclusions may be 
drawn: Ist, that iodine, bromine, and chlorine are noncon- 
ductors; 2ndly, that they improve the conducting power of 
badly-conducting eiectrolytes; and 3rdly, that two noncon- 
ductors combining can form a body which can conduct electri- 
city, and which resists the decomposing power of the voltaic 
battery. 
7, Curzon Street, 15th January, 1836. 
XXVI. Description of the Aurora Borealis of November 
16, 1835. By W.Sturceon, Lecturer on Experimental 
Philosophy at the Honourable East India Company's Military 
Academy, &c. &c.* 
N aurora borealis of a very unusual character was seen in 
this neighbourhood, and I imagine over a large tract of 
country, on Wednesday evening the 16th instant. I was 
walking from Greenwich to Woolwich between nine and ten 
o’clock; and when I had arrived at the top of Maize Hill, by 
the side of Greenwich Park, then about ten minutes past 
nine, my attention was first attracted by the fine light of the 
aurora in the north. I walked on a little further till a good 
opening to the northern horizon presented itself from the road 
leading from Maize Hill to Mr. Angerstein’s estate. At this 
opening I made a determined stand, for the purpose of observ- 
ing any novel phznomenon which the aurora might happen 
to present. 
At this time it consisted principally of a very extensive la- 
teral range, on both sides of the pole star, of vertical streamers, 
which were pencilling thenorthern heavens from about 15° 
above the horizon to Cassiopeia’s Chair, then about the meri- 
dian; and so uniform was their arrangement and splendour 
that they presented one sheet of yellowish white light, the 
most intense at the base, and becoming more and more faint 
as they proceeded upwards, until quite lost at their terminal 
altitudes. 
This appearance of the aurora had but just stamped its im- 
pression on my mind, when in one moment the whole of the 
northern heavens appeared in one complete state of undulat- 
ing commotion, heaving upwards in rapid succession immense 
waves of lightt, which, like the streamers which preceded 
* Communicated by the Author. 
+ These waves were seen at Milton next Gravesend by my scientific 
friend Mr. Swinny ; and I beg to acknowledge the obligation I am placed 
