In the news today is the discovery of "Britain's oldest house". Found in Scarborough, North Yorkshire, it is estimated to have been built in 8500 BC.
But I prefer another story, which is getting much less attention, about the discovery of a 4000-year-old scalpel blade made of obsidian. Hürriyet News reported yesterday that it was found by archaeologists excavating a site called Ikiztepe Village in the Black Sea province of Samsun, in modern day Turkey.
In charge of the excavations is Istanbul University's Onder Bilgi. He says that the scalpel would have been used in ancient brain surgery.
Intriguing... Yesterday's Hürriyet article doesn't say why Bilgi believes the blade was a scalpel but a small amount of digging turns up an earlier report from the dig site, published on 28 July, which says that 8 out of 690 skulls discovered at a graveyard on a high hill near the village showed "traces of surgical operation".
Actually this isn't as far-fetched as it sounds. There are records of neurosurgery from Babylon and Egypt, using obsidian blades, from as far back as 3000 BC. And skulls bearing traces of centuries-old brain surgery have been found in Europe, Africa, Asia and North and South America. The earliest trepanned skulls date from the Neolithic stone age (see main picture, of a Neolithic girl's skull now held in the National History Museum in Lausanne, France; she survived the surgery).
In the 2005 book Textbooks of Operative Neurosurgery, in a chapter about drills in neurosurgery, Trimurti Nadkarni and Atul Goel write that there would have been three main techniques for getting through the skull - scraping, trepanning and cutting. In the earliest examples, a sharp-edged flint scraper or knife would have been used to make a circular or rectangular groove in the skull.
In ancient Peru, knives of bronze or obsidian were used. The wound was covered with a shell, a gourd, or even a piece of gold or silver. More recently, surgeons would have used a bow drill, made of springy wood with a leather thong wound around it.
So why obsidian? It's a naturally-occurring volcanic glass. It is formed when volcanic lava with a high content of silicon dioxide (silica) cools rapidly. The high silica content makes the lava very viscous, meaning that sizeable mineral crystals can't form before the magma cools. The absence of crystals in the glass means that when it breaks, the fracture surface is very smooth, with extremely sharp edges.
Obsidian was used for ancient projectile points and blades, including a very nasty Mesoamerican weapon called a macuahuitl, which was a 3 to 4-foot-long wooden club, with obsidian blades embedded in it (see pic). It was also polished to create early mirrors.
In fact obsidian blades are sharper even than surgical steel blades, so some modern surgeons advocate using obsidian scalpels today. A 1993 study on rats showed that cuts made with obsidian blades initially formed narrower scars, and healed quicker, than cuts made with surgical steel scalpels. Unfortunately such blades are not generally approved for use on humans, so it looks like we will be sticking with steel scalpels for a while yet.