The Testamentum Theorica is the earliest work in the Pseudo-Lullian Alchemical corpus, a large collection of as many as 143 different texts that circulated as the work of Raymond Lull (Ramon Llull or Raimundus Lullus; 1232-1316), the famous Catalan philosopher, theologian, and mystic. The Testamentum was likely written by an anonymous fourteenth-century Catalan scholar, now known as the “Magister Testamentum,” who probably studied medicine at Montpellier and was active in Catalonia, Southern France, and England. This particular manuscript, which includes only the first book of the Testamentum, is an early copy, made in England, of the Latin version of the text, likely dating within twenty-five years of the first translation of this text from Catalan into Latin.

A seminal text in the development of medical alchemy (a discipline associated in the sixteenth century with Paracelsus), the Testamentum was one of the first texts to develop the idea of the elixir, or the philosophers’ stone, as the agent of the general perfection of matter – able to “cure” the imperfections of base metals and thus turn them into gold, as well as to “cure” precious gems, and to maintain human health by curing disease, and thus prolonging life. While the first book of the Testamentum is largely theoretical in content, it does include a series of practical, alchemical recipes in Latin and English. Notably, this particular copy bears copious evidence of use, including contemporary corrections and annotations.