180 ANNUAL OF SCIENTIFIC DISCOVERY. 



dcrful nebula of Orion and in several others. Now, this nebula 

 ot Orion "was believed by Lord Kosst to have been eompletely re- 

 solved by h\s teleseope into separate points oflight, and we should 

 thus be led to conelude that it is, in faet, a vast sj'stem — a uni- 

 verse of suns or luminous centres, none of them solid, however, 

 but all, on the contrary, vast spheres of glowing gas, that gas be- 

 ing ehietly hydrogen, mixed with nitrogen. When, in ]\Iay, 

 18IJG, a star in the constellation of the Northern Crown suddenly 

 burst forth with unprecedented splendor, and when examined 

 with the spectroscope showed a spectrum such as had never be- 

 fore been encountered, consisting of such a one as our sun or 

 an ordinary star gives, but with 4 bright lines, due to a gaseous 

 source of light, superi^osed, it was found that two of these lines 

 (and those the most brilliant) were such as come from light 

 emitted by intensely hoated hydrogen. The natural conclusion 

 from this was, that some half extinguished star or sun had been 

 encountered by one of these nebulous masses of hydrogen, or 

 else by some vast globe or jilanetary cloud of the same gas, 

 which had lost its heat and ceased to be luminous. This true 

 *' planet" or "wandering sphere " of hydrogen, coming within 

 range of the star's attraction, was drawn down to it, ami, by the 

 arrest of motion and compression consequent upon its encounter, 

 was itself heated to incandescence, and heated also the surface of 

 the dead sun to a temporary but intense brightness. Here, then, 

 was presented the spectacle of a world on tire, in which the agent 

 of destruction, or reconstruction, whichever it might be, was one 

 of these celestial masses of hydrogen gas. It is curious to re- 

 fl(>ct, in this relation, that, making due allowance for the probable 

 distance of this star and the velocity of light, this sphere had been 

 at rest for some 10 or 12 years after its liery ordeal, at the time 

 when we witnessed the event as in actual progress. When, about 

 a year since, (jraham subjected pieces of meteoric iron to the 

 same treatment which had, in the case of ordinary iron, elimi- 

 nated the carbonic oxiie which it had absorbed while underiroinjr 

 fusion in the smelting-furnace, it was hydrogen gas in large quan- 

 tity which was evolvcnl ; thus proving that in the furnace in which 

 these •' falling stars " were fused and cast into shape, this same 

 widely di>tributed element was again ])redominant. Lastly, in 

 th<>se spectroscopic observations and discoveries in connection 

 with the sun, which we described in our last number, it seems to 

 be very clearly shown that hydrogen gas is again the main con- 

 stituent of that which Lockyer proposes to call the solar " chro- 

 mosphere," which surrounds the entire mass of our luminary for a 

 depth of some 5,000 miles, and forms those flames or protu- 

 berances, a single tongue of which, as in the last eclipse, may 

 contain some 7,000,000,000,000 cubic miles, or 27 times the 

 earth's volume of this gas. We have reason, therefore, to wish 

 that our knowledge of these solar appendages may not become 

 too intimate, and that none of them may, by an excursion to this 

 distance, furnish to other planets, at onr expense, a second dis- 

 play of the phenomena exhibited in t Coronae Boreaiis. 



