Croup, for Baby or Older Child

"Take a teaspoonful alum, pulverize it and sprinkle it on the whites of two fresh eggs in a cup or glass, let it stand for a few minutes, until the combination has turned to water, or water is produced; then give one-half teaspoonful to a child six months old or less and increase the dose to one teaspoonful for older children, and repeat the dose in fifteen or thirty minutes as the case may require. Remarks: From personal experience in my own and neighbors' families, I have never known a case where it did not bring relief and cure. The dose must produce vomiting."

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