comets than most people), I should not have hesitated to answer these questions in the negative, and have said that all comets exhibit a more or less silvery-grey hue. On the other hand, however, there is a certain amount of evidence available which conflicts with this statement. Passing over what I cannot but consider the sensational assertions of many ancient and mediaeval writers of comets appearing of the colour of blood, or fiery red, and so on, we do find in the writings of modern astronomers sufficient evidence to show that such tinges as "yellowish", or "yellow", or "ruddy", are not unprecedented both as regards nuclei and tails. The Comet of 1769, the great Comet of 1811, the great Comet of 1843, Donati's Comet of 1858, Coggia's Comet of 1874, and Fabry's Comet of 1886 (i.),[1] are cases in point. To this it must be added that in a few rare cases mention is made of "bluish-green" as a tinge which has been noticed. After all said and done, however, I find that in looking into the published accounts of many comets by many observers in different parts of the world, there is a decided preponderance of testimony in favour of "white" or "silvery-grey", or something of that sort, as being the ordinary hue of most comets.
- ↑ "Ruddy brown" is the expression used in this case. Month. Not. R.A.S., vol. xlvi, p. 436. June 1886.
