160 HISTORY OF THE [1860-70 But the first-fruits gathered in those early years were remarkable enough, showing as they did that the stars differing from one another in the kinds of matter of which their spectra could give evidence are constructed upon the same model as the sun, and are composed of matter identical, at least in part, with the materials of our own system. Huggins's work on the nebulae roused even greater interest than his studies of the stellar spectra. Lord Rosse had inferred from observations made with his 6-foot reflector at Parsonstown, that many nebulae which had not been resolved into starry clouds with less powerful instruments could be seen in his giant telescope as clusters of minute stars. The year 1864 saw Huggins's discovery of the gaseous nature of eight planetary nebulae, proving that they could no longer be regarded as aggrega- tions of suns after the order to which our sun and the fixed stars belong, and that we must regard them as enormous masses of luminous gas or vapour. The first steps in the solution of part of the mystery of a comet as well as that of a new star were made by Huggins in the years of this decade. Some confusion still exists between the work of William Allen Miller and William Hallowes Miller [1801-80]. The former was Assistant Lecturer to Professor Daniell at King's College, London, and became Professor of Chemistry in succession to Daniell at his death in 1845. William Hallowes Miller was Professor of Miner- alogy at Cambridge (1832-80). It was he, who in 1833 made experiments conjointly with Daniell, on the discontinuous absorp- tion spectra of iodine and bromine. It was he also who verified the coincidence of the bright sodium lines with the dark D lines in the solar spectrum some years before Kirchhoff's classical work in 1859. In the correspondence which passed between Thomson and Stokes five or six years before Kirchhoff's celebrated Memoirs, and which was found by Sir Joseph Larmor in arranging the scientific correspondence of Stokes (Collected Papers, 4, 367), references to the work of Miller occur in several places ; and the Miller there named was William Hallowes Miller. The meeting of the Society on 1866 December 14 was a specially interesting one, for at it were received accounts of the observations of the Leonids. A. S. Herschel gave the position of the radiant determined by fifteen observers. Airy told of 8500 meteors having been counted at Greenwich. In anticipation of a display of meteors, such as had been observed by Humboldt at Cumana, near the northern coast of South America, in 1799, and by many observers in 1833, consider- able attention was given to the observation of meteor tracks, especially in the years of this decade. Humboldt had failed to
