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

is ready, and well seen, contact is made, and it is thus heated ; and from the brilliancy of the clear and distinct light there produced, the tooth-pulp is all the better seen, and can be accurately touched, and only so, with the heated wire, when the whole, or the particular portion of it required, is instantly destroyed." It is well to mention, that caution is to be observed not to injure the solid part of the tooth. Particular care should be paid to this point. This will not happen unless the application is prolonged, which is almost never required, and if special care be observed to have the wire at a white heat. This is the more necessary, to produce the sure and speedy destruction of the soft part touched, which indeed is effected almost instanta- neously. " In one instance," says Dr. Harding, " that of a lady for whom I nipped off the crown of an incisor tooth, for the purpose of fixing some artificial teeth, and so exposed the pulp of that tooth, I applied the electric cautery at barely a red beat, owing to the feebleness of the acid in the battery. The unfortunate consequence of this was, that the dental pulp became attached to the end of the wire, and was actually drawn out of the tooth entirely. This has been preserved as a patho- logical specimen. It gave some slight pain for the moment, but mere nothing in comparison to the pointed steel, or silver wire, as used by most dentists. This perhaps unimportant accident, I think, would not have occurred had the cautery been at a white heat, as it would then have as completely as quickly destroyed the soft part with which it came in contact." " The effect of this operation," he says further, " is the rapid annihilation of the pulp of the decayed and condemned tooth. Not the whole of the pulp, for that is not always necessary; but that portion of it, especially, which is exposed. If this is adroitly done, with a light, steady hand, no subsequent inflam- mation is produced in the substance or cavity of the tooth. If there should be any marked sensitiveness in the tooth, inde- pendent of the pulp, then the slightest touch of the cautery to it will prove effectual in completely removing it. In the large number of cases in which I have employed the galvano-cautery,