I

Potassium nitrate...     2    pounds

Ammonium chloride    2    pounds

Water.............     5    pints

II

Potassium nitrate. ..     2.5 pounds

Ammonium chloride    2.5 pounds

Sodium sulphate... .     4 pounds

Water.............     9 pints

III

Ammonia nitrate... 4 pounds Water............. 4 pints

IV

Sodium sulphate. .. . 8 parts Dilute hydrochloric

acid............ 5 parts

V

Snow............. 1 part

Water............. 1 part

Sulphuric acid...... 4 parts

VI

Snow.............. 3 parts

Calcium chloride. .. 4 parts

Refrigeration

If water to be frozen is placed in a tin bucket or other receptacle it can be readily congealed by putting it in a pail containing a weak dilution of sulphuric acid and water. Into this throw a handful of common Glauber salts, and the resulting cold is so great that water immersed in the mixture will be frozen solid in a few minutes, and ice cream or ices may be quickly and easily prepared. The cost is only a few cents. The same process in an ice-cream freezer will do the trick for ice cream.