should see the luminous hydrogen and associated gases boiling upward, and thence drawn forward from the nucleus by the combined gravity of the sun's mass, that of the planetary masses, and the opposite polarity of the planetary electrospheres, while they would be, at the same time, repelled backward by the enormous repulsive force of the negative electrosphere of the sun. As a result, we should find these gases in a state of ebullition, forced forward under great excitement and disturbance, boiling, eddying about, driven to and fro in all directions until the sun's repulsive force had overcome the different attractions, when these luminous clouds or envelopes would be swept swiftly off to the rear, as by a powerful current of wind, around the margins of the nucleus, and they would be seen to stream backward from the sun as an elongated envelope or tail. New volumes of gas would pour to the front, attracted from deeper depths, and these, on reaching the cometary electrosphere, would be again repelled by the solar activity and driven to the rear, while the gases thus driven backward, themselves similarly electrified, would mutually repel each other as they streamed backward around the margins of the nucleus. Let us now see what these gases are: if they are such as appear in the sun's electrosphere, we will know that such must be their action; if, on the contrary, they are such as appear in planetary electrospheres, we will find any such attempted explanation to be a failure. Quoting largely from Dr. Huggins, Professor Proctor, in his "Cometic Mysteries," says, "The spectrum of the brightest comet of that year was partly continuous, and on this continuous spectrum many of the well-known Fraunhofer lines could be traced. This made it certain that part of the comet's light was reflected sunlight, though Dr. Huggins considers also that a part of the continuous spectrum of every comet is due to inherent light. On this point some doubt may be permitted. It is one thing for special bands to show themselves, for some substances may become self-luminous under special conditions at very moderate temperatures; it is quite another thing that the solid parts of a comet's substance should become incandescent. I venture to express my opinion that this can scarcely happen, except in the case of comets which approach very near to the sun. Besides the continuous spectrum with dark lines, the photograph showed also a spectrum of bright lines. 'These lines,' says Dr. Huggins, 'possessed extreme interest, for there was certainly contained within this hieroglyphic writing some new information. A discussion of the position of these new lines showed them to be undoubtedly the same lines which appear in certain compounds of carbon. Not long before Professors Liveing and Dewar had found from their laboratory experiments that these lines are only present when nitrogen is also present, and that they indicate a nitrogen compound of carbon,--namely, cyanogen.