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 upon this extraordinary celestial phenomenon. He found the spectrum of the star to consist of two distinct spectra, one being formed by four bright lines, the other analogous to the spectra of the sun and stars. Consequently two kinds of light were given off by this star; one forming a series of bright lines indicative of luminous gas, the other consisting of a continuous spectrum, crossed by dark lines, showing the existence of a solid body in a state of incandescence, surrounded by a photosphere of luminous vapours. Two of the bright lines undoubtedly showed the presence of hydrogen in a state of illumination, the great brightness of the lines indicating that the burning gas was hotter than the photosphere. These facts taken in conjunction with the suddenness of the outburst in the star, and its immediate decline in brightness from the second down to the eighth magnitude in twelve days, suggest the startling speculation that the star had become suddenly wrapped in the flames of burning hydrogen, consequent possibly on some violent convulsion in the interior of the star having set free enormous quantities of this gas. As the free hydrogen became exhausted, the spectrum showing the bright lines gradually waned until the star decreased in brilliancy. It must not be forgotten that the event seen by Mr. Huggins occurred many years ago, and that the light emitted by this marvellous celestial convulsion has been travelling to us ever since.

Comets and meteors have been submitted to the test of spectral analysis. The former erratic visitors have been but few and small since stellar spectrum analysis has been perfected. In January 1866, Mr. Huggins brought his apparatus to bear upon a small comet, which gave a somewhat unexpected result. When the object was viewed in the spectroscope, two spectra were distinguishable—a very faint continuous spectrum of