The remedy which beyond all comparison succeeded best, was sulphate of copper. The usefulness of this substance, though known at Salem, New Jersey, was discovered, at the Asylum, by the mistake of a nurse. It had been previously used, in lotions of the strength of gr. ij or iij to the ounce of water; and with little advantage. Observing that the empirical remedies said to have succeeded, were, as I considered them, immoderately strong, I furnished the nurse with a common solution of sulphate of copper, and with a vial containing 72 grains of the sulphate in an ounce of water, for the purpose of being progressively added to the other at different periods. This stronger solution was applied, by mistake, instead of the diluted one; and it was the first remedy which had produced a rapid tendency to a cure. I finally settled down, after various trials, in the employment of the following: R. Sulph. Cupri, [Symbol: dram]ij Pulv. Cinchonae, [Symbol: ounce]ss Aquae, [Symbol: ounce]iv _m._ S. To be applied twice a day, very carefully, to the full extent of the ulcerations and excoriations. The cinchona here is not absolutely necessary; but operates by retaining the sulphate longer in contact with the edges of the gums. Simple ulcerations and small gangrenes, as well as the troublesome excoriation, when not in the last stage, yielded promptly to this remedy; the good effect being generally visible from the first application. Dr. FOX, my friend and fellow-labourer in the Asylum, had already taught me that it was important early to extract the teeth. I was not, however, sensible of the full extent of this rule, till after examining the fangs of some of them which were drawn. The separation of a portion of the periosteum from the fang, within the socket, which was universally found whenever the tooth was loose, among two or three hundred specimens, proved the existence of the disease in a deep, narrow crevice, into which it was impossible, by any contrivance, to insinuate the lotion. This cavity was laid open by extracting the tooth; and when the remedy was applied, the sanatory effect was surprisingly prompt. From this period, forwards, the universal rule was to extract all teeth, the moment they were discovered to be in the slightest degree loose; and "the blue wash" above described, became the standing remedy.