Title page from Pharmacopoeia Londinensis, published in England, 1632. A pharmacopoeia is a reference work for pharmaceutical drug specifications. The compounds employed in medicine were often heterogeneous mixtures, some of which contained from 20 to 70 ingredients which sometimes called for the excrementsof human beings, dogs, mice, geese and other animals, calculi, human skull and moss growing on it, blind puppies and earthworms.