In a ‘groovy’ turn of events, archaeologists have identified how cannabis might have played a crucial role in supporting the antediluvian walls of a UNESCO World Heritage Site. We are talking about the Ellora Caves, a fascinating 1,500-year old archaeological site comprising both Brahmanical and Buddhist group of caves (consisting of rock-cut temples and viharas), situated in the Indian state of Maharashtra. According to a recent collaborative study conducted by researchers from the Archaeological Survey of India and Dr Babasaheb Ambedkar Marathwada University, the painted walls and ceilings of these man-made caves were composed of a definitive mixture of cannabis, clay and lime. To that end, by chemical analysis, it was found that the cannabis component played quite interesting role in preserving the architectural unis by intrinsically strengthening the plaster.
For the research, the experts utilized a scanning electron microscope, infrared spectroscopy and stereomicroscopic studies. They were successful in isolating the cannabis from a ‘micro’ part of the plaster, thus suggesting its inherent role in the composite clay used for the supporting structures of the caves. From the chemical perspective, cannabis (known as ganja in India, and used for the bhang concoction) was probably utilized in the plaster for its insulating quality. Furthermore, the cannabis fibers apparently showcased higher degree of durability when compared to other fibers, and thus its ‘sticky‘ nature might have helped to form a strong binder with the clay and lime.
When translated to practicality, the binding composite transforms into what is called hemp-crete, a durable concrete-like plaster that was conducive to heavy-duty nature of these ancient walls and ceilings. The researchers made it clear –
[Hemp-crete plaster allowed for] a healthy, comfortable and aesthetically pleasing living environment to the Buddhist monks to stay. As the hemp plaster has the ability to store heat, is fire-resistant and absorbs about 90 percent of airborne sound, a peaceful living environment for the monks has been created at Ellora Caves.
Now if we come to the numbers game, it should be noted that cannabis only accounted for around 10 percent of the clay plaster in question here. But this small percentage alone did endow the plaster with self-preserving quality that allowed it to be sustained for over 1,500 years. In that regard, a separate study conducted in Europe established how hemp-crete could last over a period of 600 years. Additionally in this case, the researchers also identified other beneficial qualities of the cannabis, including its ability to regulate humidity inside the rock-cut temples, anti-toxic filtration capacity, and the capability to allow diffusion of vapor. But as the experts noted –
Unfortunately in India cannabis has gained a bad name because of its narcotic properties. But the ancient artists knew its good sides.