Monthly," the theory to which my own researches have led me—the more so, that I find my ideas quite commonly misapprehended, insomuch that objections have been urged (as by Professor Newton and by my friend Professor Young) which, though, full of force in themselves, have no bearing whatsoever on my theory as it really is.
I may say, indeed, at the outset, that I am in thorough agreement with all or very nearly all which Professor Newton has urged in the way of objection against the views of those who have theorized on this subject on special lines, including the view (which he attributes to myself) that comets and meteors have been expelled from the sun, or from the giant planets. But, at the same time, I find in all those theories, including even the one mistakenly attributed to myself, the germs of truth. If Schiaparelli is quite mistaken in regarding comets as captured meteor-flights, we yet owe to Schiaparelli the now established theory, admitted by all (unless Mr. Denning can be counted as an exception), that meteors are closely connected with comets, and the probable theory that comets are in reality flights of meteors, though their origin in our system may not be that which Schiaparelli has assigned to them. Again, Tschermak is undoubtedly mistaken in supposing that meteorites were originally expelled from the earth's interior, yet the evidence which he has adduced to show that a certain class of meteoric bodies most probably had such an origin can not be lightly overlooked. In like manner when Daubrée speaks of meteorites as having had their origin in the stars, and regards all orders of them as telling us of stellar interiors, he unquestionably lays himself open to the objection that certain orders of meteoric bodies can not possibly have had that origin, their orbits being entirely inconsistent with any such supposition. Yet, in the work Daubrée has done to indicate the conditions under which meteorites were first formed, he has as unquestionably supplied material, of which the true theory, whatsoever it may be, must take account. So with the theory which I have been supposed to entertain. It is manifest that bodies shot forth from the sun would either return to him, or, if their velocities of ejection were great enough, would pass away not only from him, but from the solar system, forever. It is manifest, also, that the giant planets can not now possess power to expel bodies from their interior with such force as would be required for absolute rejection as distinguished from mere temporary ejection; and certainly nothing in the present condition of our earth, or in the evidence given by her crust as to past volcanic action, suggests the likelihood, if even the possibility, that during her career as a planet she has had the power of rejecting matter from her interior.
But I have mostly found that, in endeavoring to form a true general theory on a subject of this kind, it is important to gather together the good features of the several special theories, not merely to note such weak features as become associated with them through a mis-
