In the Receipts, & c. Section
Pickling. – Do not keep pickles in common earthenware, as the glazing contains lead, and combines with the vinegar. Vinegar for pickling should be sharp, though not the sharpest kind, as it injures the pickles. If you use copper, bell-metal, or brass vessels for pickling, never allow the vinegar to cool in them, as it is then poisonous. Add a teaspoonful of alum, and a teacup of salt to each three gallons of vinegar, and tie up a bag with pepper, ginger-root, spices of all different sorts in it, and you have vinegar prepared for any kind of pickling. Keep pickles only in wood or stoneware. Anything that has held grease will spoil them. Stir them occasionally, and if there are soft ones, take them out and scald the vinegar, and pour it hot over the pickles. Keep enough vinegar to cover them well; if it is weak, take fresh vinegar and pour on hot. Do not boil vinegar or spice above five minutes.
*Please note that the information provided in this post has NOT been tested for consumption by humans or other living creatures. This information is for research ONLY.