Microscopic analysis of residues on surgical scissors and tweezers from a 1348-1411 CE tomb in Jiangyin, China finds the first evidence for the controlled application of a highly toxic chemical as anaesthetic, highlighting the sophisticated medicine of the Ming dynasty.
From Roman cosmetics to Andean psychoactive plant preparations, archaeologists often apply scientific methods to identify pharmaceutical residues from ancient civilisations.
However, conventional techniques are difficult to apply to ancient Chinese medical residues, which are rarely preserved and often fail to meet minimum sample requirements for identification.
To tackle this, archaeologists used a novel, non-destructive microscopic technique to analyse residues on a pair of surgical scissors and tweezers from the tomb of early Ming dynasty physician Xia Quan.
“Stimulated Raman scattering (SRS) microscopic imaging is an advanced optical technique that can be used to accurately identify material compositions and map component distribution, effectively overcoming the key challenges in residue research of minimal sample availability and the need to preserve archaeological material”, says co-author of the research, Professor Congcang Zhao from Northwest University.
The researchers found evidence for residue of aconitine: an alkaloid derived from the plant Aconitum. Also known as wolfsbane or monkshood, Aconitum is extremely toxic.
This toxicity was recognised and several methods to mitigate it had been developed by the time of the Ming dynasty, from vinegar-boiling to detoxifying with mung beans. The resulting powder acted as an anaesthetic, enabling pain-free surgery.
Whilst recipes for the production of Aconitum powder are known from ancient Chinese medical texts, this is the first direct physical evidence for its use in surgery.
It was likely applied to the patient’s skin to numb the area before incisions were made, requiring meticulous application and strict control to mitigate toxicity.
“Combined with records of anaesthetic prescriptions in Ming Dynasty medical texts, the study confirms that Aconitum was employed as a topical anaesthetic, safely and precisely applied during surgical procedures”, explains Professor Zhao. “Ming physicians used iron surgical instruments and controlled the toxicity of aconitine through topical application, compound prescriptions and strict procedural controls, demonstrating a practical ability to balance drug potency with patient safety.”
Medical professionals in Ming China were therefore not only highly knowledgeable in the production of anaesthetic, but also in its safe use, highlighting sophisticated medical knowledge and surgical techniques as early as the 14th century CE.
“Six centuries ago, a Ming Dynasty surgeon performed an operation with a pair of iron scissors and tweezers, and today we have read the traces of anaesthetic medicine left on those instruments using a beam of laser light”, Professor Zhao concludes—this is the first time humanity has found direct chemical evidence of anaesthetics on ancient surgical tools, proving that our ancestors already knew how to safely alleviate patients' pain with highly toxic herbs.”