The mid-to-late 16th century would see major developments in the medical fields of anatomy and surgery. Andreas Vesalius published the first comprehensive anatomical textbook in 1543, which he based on his own firsthand observations collected from numerous human dissections. Similarly, a battlefield surgeon named Ambroise Paré published a text in 1545 that presented new ways to treat firearm and artillery wounds. Based on his war experiences, Paré also recorded valuable observations about the use of ligatures to staunch blood flow from horrific wounds or amputations. These mid-century medical advances, however, were not known to the members of Hernán Cortés’ expedition that set sail for Mexico in 1519. At the time of their adventure, European medicine was still dominated by the ideas of the Greek-Roman physician, Galen (d. 213), as well as other slowly evolving traditional folk remedy beliefs.
According to Bernal Díaz del Castillo, a veteran conquistador in Cortés party, the common medical practice among his comrades was to treat any wounds they sustained with oil or grease. He did not mention if, as was common at the time of the expedition, the oil happened to be boiling-hot when applied to the wound—this painful cauterization technique was later argued against by the aforementioned Ambroise Paré. Yet, Bernal Díaz did claim that if whatever greasy substance they used had congealed or solidified, they would melt it down before use. Furthermore, it is unclear how this melted or warmed oil or grease was applied; he never described his comrades as ‘cauterizing’ wounds. Instead, Bernal Díaz’s statements about the subject are most often translated to mean that the conquistadors ‘dressed’ their wounds with the oily substance.
After being on the expedition for several months, however, the oil supplies of the conquistadors began to run low. Faced with this shortage, the Spaniards had to be creative on how, and with what, they would heal their wounds. As may be expected, for their first medical experiments, the conquistadors decided to do some animal testing trials, and therefore began to treat their horses’ wounds with a new greasy material that they found in Mexico. A fair warning, the descriptions of this new healing method used by the conquistadors is not for the faint of heart.
The conquistadors apparently had a medical epiphany around the time of the Battle of Cintla, fought on March 25, 1519, in the Tabasco region of Mexico. After the battle, hundreds of natives reportedly lay dead on the battlefield. Cortés had brought all the latest weaponry to the battle—fine swords, crossbows, firearms and cannons. Therefore, many of the corpses scattering the field were sliced open or blasted apart. While surveying this field of carnage, the Spaniards noticed a new substance among the gore that they believed could be used to treat wounds—human fat. Bernal Díaz made an account of his comrades’ first experimentation with this new substance, which they tried out on their horses. He wrote, “we bandaged the wounds of our men with linen, which was all we had for that purpose. Those of our horses we dressed with melted fat, which we cut from the dead bodies of the Indians” (Conquest of New Spain, chapter 34).
By September, the Spaniards were convinced enough by the health of the horses to try the fat on their own wounds. Around September 1, 1519, after having fought against an ambush of Tlaxcalans or Otomis, the conquistadors desecrated the corpse of one of their foes in order to seal their wounds. Bernal Díaz wrote, “we dressed our wounds with the fat from a stout Indian whom we had killed and cut open, for we had no oil” (Conquest of New Spain, chapter 62). They would repeat this procedure the very next day, when they encountered an even larger native force.
Written by C. Keith Hansley
Picture Attribution: (Painting of Francisco Pizarro and conquistadors, by Juan Lepiani (1864–1932), [Public Domain] via Creative Commons).
- The Conquest of New Spain by Bernal Díaz, translated by J. M. Cohen. New York: Penguin Books, 1963.