2oz of Pearl Ash also known as Potassium Carbonate. Packaged in a modern plastic bottle with a safety lid.
According to the Oxford Symposium on Food and Drink, Pearl Ash (potassium carbonate) was used as a chemical leavening agent as early as the 14th century in certain Dutch Baking. It is an alkaline, similar to modern-day baking soda, that is refined from potash - a crude alkaline compound derived from burnt wood and other plant material. When combined with an acid (such as sour milk, vinegar, honey, or molasses) pearl ash produces carbon dioxide. The carbon dioxide becomes entrapped in the dough or batter as it bakes, resulting in a lighter crumb in the finished cake or bread. We have found mention of its professional use by English Bakers as early as the mid-18th century. The earliest culinary reference we have found is Amelia Simmons' 1796 cookbook, American Cookery, however, other period references suggest it may have been in use by home bakers long before that in the northern colonies. Its use became widespread in North America by the early 19th century.