passes through the book, and thus reaches the sensory nerve, and that, but for the intervening book, it would not pass that way? Under some circumstances, it might be that a conductor would facilitate the passage of a "something" which would not pass through the air, but in this case there is the difficulty of getting this "something" to the book, and then of sending it forward through the air. The only alternative seems to be to suppose that when there was no intervening book, a "something" passed to the frog which was necessary to cause it to jump directly forward, the passage of which the book prevented. Neither of these hypotheses seems satisfactory, even if no objection is made to the unknown "something."
To those skilled in scientific investigation it may not appear important, but I apprehend that many, like myself, not familiar with its modes, will regret that the experiment in this case was not pushed somewhat further. To find, for instance, what would be the effect when the obstruction extended equally to the right and to the left? What if it extended indefinitely both ways? And what, when it made an entire circle around the frog in the centre; and what if in different positions other than the centre.
But, even admitting, in all the cases, all that Prof. Huxley claims as ascertained facts, what does it all amount to further than that he has brought to light some additional phenomena which, like the movements of the material universe and the pulsations of the heart, must be referred to some inscrutable agency? He who believes only in intelligent power refers them, with all else that he does not effect by his own efforts, and which he regards as beyond the power of any known embodied intelligence, to a Superior Intelligence, acting through the instrumentality of matter or otherwise; while he who believes only in material causation attributes them to the influence of matter, in some form or some mode of its movement differing from those forms and modes which are familiar to him. Nor is it material how many steps there may be between the power applied and the effect. If there are three or thirty ivory balls in a right line, and the first of them is put in motion causing each one successively to impinge on the next, the final effect of motion in the last is caused by the power applied to the first. We may by our own efforts put the alleged power of matter in action, or may thus act through the uniform modes of God's action.
In voluntary muscular movement the intermediate effect of a flow of blood to the contracting muscle has long been known; now, the propagation of molecular movement is ascertained. That we are not conscious of the movement of the molecules indicates (though far from conclusively) that we do not ourselves move them, but this does not indicate that the muscular movement is not the result of our own effort working through other agencies. That he who throws the stone which kills a bird does not know what curve the stone will describe, nor by
