Is this penetration physically possible?–Oometary influences, according to Dr. Foxster –Were the dry fogs of 1783,1831, and 1834, due to the tails of comets?–Volcanic phenomena and burning turf-beds; their probable coincidence with fogs–Probable hypothesis of Franklin–Dry fogs, atmospheric duat, and bolides.

We perceive, then, that the influence of comets upon living beings by the action of heat is a hypothesis which, for the present, must be abandoned ; in so far, at least, as the action of heat by radiation from a distance is concerned. We have throughout reserved the questions of a collision between the two bodies, and of the penetration of the earth to the heart of a mass in a state of incandescence.

Apart from the action of calorific radiation, what influence of any other kind could a comet exercise upon the meterological conditions of the earth? We know of absolutely none.

It remains, then, to consider the immediate physical or chemical influence of the cometary substance. It is not forbidden to our globe, as we have seen, to traverse the gigantic trains which form the tails of certain comets, nor to penetrate to a certain depth the vaporous atmosphere of some amongst them. Apart from these rencontres, we may suppose that cometary matter may be introduced into our atmosphere by the power of attraction.