Finger Nail Powder, Old Tried Remedy for

"Violet Talcum Powder 1/2 ounce
Pulverized Boric Acid 1/2 ounce
Powdered Starch 1/2 ounce
Tincture of Carmine 15 drops

If the nails become hard or brittle, immerse them in warm olive oil every
night or rub vaselin into them."

Source: Mother's Remedies: Over One Thousand Tried and Tested Remidies from Mothers of the United States and Canada, T. J. Ritter

After Receiving A Bruise On The Finger Nail

plunge the finger into water as hot as can be borne. By doing so the nail is softened, and yields so as to accommodate itself to the blood poured out beneath it, and the pain is soon diminished. The finger may then be wrapped in a bread-and-water poultice. On the following, or on the third day, the blood has clotted; and separating into its clot and fluid parts, the pressure it makes on the sensitive skin under the nail may be relieved by scraping the nail with a penknife till it becomes so thin that the scraping causes pain. The thin nail left is very light, and the pressure is mitigated; but if the squeezed part of the nail be very black, and tender when touched, it is best, after scraping, to make a nick through the remaining nail over the black blood, and immediately the watery part gushes out, the pressure almost entirely ceases, and instantaneous relief is afforded, but it unfortunately rarely, if ever, prevents the nail from coming off.

Source: Home Notes, January 1895.