164 Miscellaneous Notices by Prof. J. F. Duna. 
ends of the enclosed steel became north, and the middle 
south ; if on the contrary, the coii began to pass from left to 
right, on the positive side, both ends of the steel acquired a 
south polarity and the middle a north polarity. When the 
jar was charged negatively, and the coil began to pass from 
right to left on the negative, both ends acquired a south and 
the middle a north polarity ; if the coil begin to pass from — 
left to right on the negative side the polarities are reversed. 
hen a wire is bent into the form of a staple (thus 
and inclosed in a glass tube surrounded by a spiral passing 
from right to left, the ends acquire anorth polarity, and the 
middle a south polarity, if the ends of the staple be next to 
the positive. If the situation of the staple be reversed, or 
if the coil pass from left to right, then the ends become south 
and the middle north. Circumstances did not permit me to 
make the experiment on a staple surrounded by the coil 
passing from right to left, and from left to right. We should, 
a priori expect, that the middle of the staple in such cireum- 
stances, would acquire the same polarity as the ends, while 
at some intermediate points on both sides of the middle an 
opposite polarity would be found, so that five poles would be 
formed in one piece, and if the wire was again doubled on 
itself, (thus ———-, ) two _ additional poles would be 
formed. _The above «xperiments were many times tri- 
ed with the same result, and have been repeated by myself 
and my friend Hon. Thos. Whipple, M. C. 
2. Preparation of Euchlorine Gas. 
I perfectly well recollect, when I bad the pleasure to be 
introduced to you at Cambridge, that the conversation turn- 
ed on the preparation of euchlorine gas ; we naturally wish 
to know whether experienced chemists meet with the same 
accidents as. ourselves, in experiments, and it was no small 
degree of consolation to learn that the laboratory at Yale 
had also witnessed accidents in the preparation of this eX- 
plosive gas.. For two years past I have prepared it in the 
following manner; strong phials capable of holding half an 
“ounce OF an ounce measure are provided, into which are put 
a few grains of chlorate of potash, and then, four or five 
drops of sulphuric acid, just sufficient to moisten the salt, 
are added ; the phials are then inverted over mercury, @- 
