Together with Ramon Llull and Arnau de Vilanova, Peratallada is considered one of the great masters of Medieval alchemy, nowadays considered something of a ‘pseudo-science’, but it was the precursor of modern chemistry before the establishment of the scientific method. The most famous compilation of alchemical texts, the Theatrum Chemicum (Strasbourg, 1659), brings together Latin versions of texts attributed to Hermes Trimegistus, the Greco-Egyptian deity that was the mythical founder of the science and its technique, as well as works by Avicenna and other Arab authors on one hand, and on the other treatises falsely attributed to Albert the Great, Llull and Vilanova, as well as various works by Joan de Peratallada, a figure considered the greatest exponent of alchemy in the Early Middle Ages.

Joan de Peratallada wrote a highly influential treatise entitled De consideratione quintae essentiae where he referred to alcohol with the terms aqua vitae or quinta essentia, which he considered a heal-all for any illness.

Together with Llull and Vilanova, Peratallada is the third of the greats of Catalan science and, like them, he is one of the great innovators of 15th-century European science.

His defence of the quinta essentia was very important as it encourage pharmacists to search for and extract other ‘quintessences’ from minerals and plants, which laid the foundations for iatrochemistry (chemical medicine) that later developed in the 16th century, founded by Paracelsus.

Ramon Llull was the first European author to describe the process of distilling alcohol. Arnau de Vilanova was the first to describe this process not as a mere theory, but with the technical details that permitted it to be put into practice and is, as such, the first person in Europe the use his discovery for therapeutic uses. Another of Vilanova’s discoveries was that alcohol spirit mixed with aromatic plants reinforced their effectiveness.