will not pass; but when the molecules of those adjacent pieces are agitated by sound-waves they transmit electricity freely. The same effect is produced by light when the metal selenium is exposed to light, and its electrical conductivity is unequally affected by the different rays of the spectrum. Prof. Hughes calls his invention the microphone, and it has this peculiarity, that the sounds are taken up directly by the "transmitter."
The London Telegraph thus refers to the results of Prof. Hughes's experiments before the Royal Society: "Inserting a 'transmitter' in his circuit, an absolutely amazing sensitiveness to sound, as well as power of conveying it with the utmost fidelity, was displayed by the apparatus. A touch of the finger on the vibrating plate of the telephone was conducted to the speaking end in volume of vibration like the rustle of a forest; the stroking of a camel's-hair brush on a card was magnified into the sound of a loud whisper; the beating of a pulse or the tick of a watch was found to pass with perfect clearness through a resistance representing a hundred miles of space; and, when a fly happened to walk over the plate, the tramp of its feet was most distinctly caught, like that of some six-legged horse trotting, and it was, moreover, heard to trumpet from its raised proboscis like an elephant in an Indian jungle. Sounds, in fact, totally inaudible before to human ears, were arrested and reported by this simple and accidental expedient of interrupting the electrical circuit with a finely-divided conducting material."
CATHOLICISM AND ETERNAL PUNISHMENT.
Under the title of "Hell and Science," a writer in the Catholic World for June makes an elaborate reply to our recent comments on the doctrine of future punishment. He is especially indignant, as might be expected, at our remark that there has been a "rapid liberalization of theological opinion" on this subject. He says that "the doctrine of hell is not a theological opinion but an inspired dogma," which, of course, can be neither liberalized nor got rid of in any other way. In speaking of the altered theological tone upon this subject, we of course referred to what currently passes under the name of theology, but our reviewer avers that we were utterly wrong in the application of the word. This is his case:
We freely admit that there is great shrewdness in this policy of the Catholics, by which so effective an instrument of domination as the fear of hell is placed beyond examination on the part of the followers of that faith. By shutting off the right of private judgment on dogmas sanctioned by authority, they no doubt get rid of the ferment of discussion and diversity of opinion which, among Protestants, follows the exercise of the right of private interpretation. The writer in the Catholic World identifies liberalism with Protestantism, and recognizes that among Protestant sects the notion of hell is dying out. He thus concedes that liberalism leads to this result,
