The best method of making a whitewash for outside exposure is to slack half a bushel of lime in a barrel, add one pound of common salt, half a pound of the sulphate of zinc, and a gallon of sweet milk.

How To Harden Whitewash

With ½ a pail of common whitewash acid ½ pint of flour. Pour on boiling water in a sufficient quantity to thicken it. Then add 6 gals. of the lime and water, and stir well.

Whitewash That Will Not Rub Off

Mix up half a pailful of lime and water, ready to put on the wall; then take ¼ pt. of flour, mix it up with water, then pour on it the boiling water, a sufficient quantity to thicken it; then pour it while hot into the whitewash, stir all well together, and it is ready for use.