The Liber Ignium ad Comburendos Hostes (translated as On the Use of Fire to Conflagrate the Enemy, or Book of Fires for the Burning of Enemies, and abbreviated as Book of Fires) is a medieval collection of recipes for incendiary weapons, including Greek fire

Greek fire

Greek fire was an incendiary weapon used by the Byzantine Empire. The Byzantines typically used it in naval battles to great effect as it could continue burning while floating on water....

 and gunpowder

Gunpowder

Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...

, written in Latin and allegedly written by a certain Marcus Graecus ("Mark the Greek")—a person whose existence is debated by scholars. The work has been subjected to numerous academic analyses, and with contradictory conclusions with regards to origin and influence on its contemporaries.

One of the most influential studies of the Liber Ignium was conducted by Marcellin Berthelot

Marcellin Berthelot

Marcelin Pierre Eugène Berthelot was a French chemist and politician noted for the Thomsen-Berthelot principle of thermochemistry. He synthesized many organic compounds from inorganic substances and disproved the theory of vitalism. He is considered as one of the greatest chemists of all time.He...

; it is still cited in 20th century works on the topic.

Contents

The Liber Ignium is a collection of 35 recipes without any internal classification, as it was typical of "secret recipe" list of the era. Of these, fourteen are related to warfare, eleven with lamps and lights, six with the prevention and treatment of burns, and four with the preparation of chemicals, chiefly saltpetre. Some recipes were found to be worthless.

Recipe no. 14 contains advice for the harvesting and processing of saltpeter. In Berthelot's interpretation, it says: "saltpeter is a mineral of the earth, and is found as an efflorescence on stones. This earth is dissolved in boiling water, then purified and passed through a filter. It is boiled for a day and a night and solidified, so that transparent plates of the salt are found at the bottom of the vessel." Furthermore, there are four recipes (nos. 12, 13, 32, and 33) that describe mixtures resembling gunpowder.

Origins and influence on contemporaries

The premillenial Byzantine Greek origin of the text has been rejected by scholars, who date it to the late 13th century. Study of the text has suggested that it was originally translated from Arabic

Arabic language

Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...

, possibly by a person from Moorish Spain.

The influence the Liber Ignium had on Roger Bacon

Roger Bacon

Roger Bacon, O.F.M. , also known as Doctor Mirabilis , was an English philosopher and Franciscan friar who placed considerable emphasis on the study of nature through empirical methods...

 and Albertus Magnus

Albertus Magnus

Albertus Magnus, O.P. , also known as Albert the Great and Albert of Cologne, is a Catholic saint. He was a German Dominican friar and a bishop, who achieved fame for his comprehensive knowledge of and advocacy for the peaceful coexistence of science and religion. Those such as James A. Weisheipl...

 has been debated. Early scholars like like the 18th century scientist Johann Beckmann

Johann Beckmann

Johann Beckmann was a German scientific author and coiner of the word technology, to mean the science of trades. He was the first man to teach technology and write about it as an academic subject....

 thought that both men had read and quoted it, but others have claimed that all three were based on a common source. Iqtidar Alam Khan writes that while the Liber Ignium contents can be traced back to Arabic and Chinese texts, the work of Bacon appears to represent a parallel tradition, especially because the decoded formulas of Bacon contain considerably less nitrate.