. 
j 
| 
: 
4 
2 
t 
; npeatsethoe magnet the positive 
y 
uming that probable cause has been shown for believing 
that the splendor of comets results directly from the excentric 
form of orbit which produces violent changes attended with the 
evolution of heat, electricity and light, I would propose to ex- 
tend the analogy to the aurora still further, and to suggest that 
whilst the tail corresponds to the auroral streamer the envelopes 
*ppear to be the exact counterparts of the concentric envelopes 
which were observed to surround one of the terminals in some of 
r. Gassiot’s experiments referred to on page 315, vol. xxxi, of 
this Journal*—the whole cometary phenomena being like the 
aurora, examples on a grand scale of the “stratified electric dis- 
charge” in vacuo, 
Prof. Peirce states that Donati’s comet had a dense nucleus of 
150 miles in di 
s, and he seems to consi ler this to be a 
Ype of the whole class, the dense nucleus and immense atmo- 
* The followi : sale « Luminous Disch of Vol- 
ea . ng quotations from an article “On the Lumino ischarges ol- 
her Batteries when feet in Carbonic Acid Vacuo, by J. P. Gassiot, Esq.. F.RS., 
acter of In the « Proceedings of the Royal Society, vol. x, No. 39,” show the char- 
these envelopes: : rae 
Page WE Vier tube “No, 146 is 24 inches long and 18 inches in circumfer- 
thee and has & copper disc 4 inches diameter at one terminal, and a brass wire 
sa t8® 399.—“In 146, with Grove’s nitric acid battery, 400 cells, on the comple- 
of the cyte the discharges of the battery passed 
. stra: 0 e j 7 
came red hot _— ich be- 
* : 
the negative being surrounded by magnizicent envelopes, whilst with 
