Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

painful, but decidedly sensible, the instant the edge of the knife or scalpel reached it, while conveying a gentle current of elec- tricity, provided the blade and back of the knife were insulated, so that the current could not reach the wound except at its very edge. This was most noticeable in opening felons. Being then, as now, perfectly aware that such currents of electricity have no sort of paralyzing power, yet it struck me that if this instanta- neously produced peculiar impression could be brought to bear upon the periosteum of the tooth while it is being extracted, it might be found to modify the sensation of pain. I did not ex- pect to find such a current, in any absolute sense an anaesthetic agent; and those who do,are hasty in conclusions, or else know too little of the laws of electro-physiology. I claim that here it is through the periosteum of the tooth, that the prc-occitpying impression of Paradaism supplants the quickly succeeding and partially simultaneous painful impression of extraction. The two impressions appear to be something like a race; but in order to have the electric impression beat the pain impression, the for- mer must have a trifle the start. I say it is probably through the peculiar properties of the per- iosteum or surface of the tooth, that this pre-occvpying or vica- rious impression overshadows the pain of tearing, and is not through the contained pulp and nerve. A recently extracted tooth, when cleaned and well dried, is almost as complete a non- conductor of the electro-magnetic current as is ivory. I do not say it is completely so, but I do say it is a very poor conductor, and cannot transmit or convey the current through its body so amply as to account for the attending phenomena. It is more probable that the current does not penetrate the tooth, but mainly passes down its sides to its nerve at its exit from the fangs, and to the contiguous alveoli. This may be true, or it may not; but such were the reasons that led me so early and so far into these trials. When several letters patent were proclaimed for the process, and litigation appeared likely to follow, I dropped this whole branch of experimentation for other fields in electro-physiology and therapeutics. At that juncture, however, the author made