By, Vikram Mitra
Ayurvedic Medicinal Cannabis Researcher, Raga Sangeet Researcher and Practitioner, Freelance Writer
Hempcrete surpasses its European benchmark of 800 years durability – it is 1500 years and still counting Hemp is one of the most versatile plants known to man to date, its uses are myriad and up until last few years it has been regaining the attention of experts from various fields, either by chance or by choice!!
Recent findings in the 6th Century Ellora Caves (An UNESCO Protected WHS site) made jointly by scientists Dr MM Sardesai and Dr M Singh from Dr Babasaheb Ambedkar Marathwada University and Archaeological society of India, shows that hemp was used as a construction material in Ancient India too.
While carrying out general renovation work inside Cave no -12, their team stumbled upon a piece of clay plaster that looked like it contained some vegetal matter, on further investigation with scanning electron microscope, it was identified as remains of Cannabis Sativa !!
The Ellora caves are a group of 34 beautiful Mono lithic Rock cut caves, stretching for 2 kilometers in North to South direction and lies on an ancient trade route passing through the present day district of Aurangabad, Maharashtra. Although, its yet uncertain about which particular dynasty built them, it is believed that three consecutive dynasties who acceded the region contributed in building these magnificent caves dedicated to Hinduism, Jainism and Buddhism, the three major religious belief systems in India.
Most striking features of these caves are intricate geometrical and floral patterns carved on their walls and murals depicting different pastimes of Lord Shiva, Mahavira and Buddha. Such artistry is not seen anywhere in the world, the detailing in each one of them is so unique that once set sight its hard to forget or not revere in the memory of it.
Pertaining to scientific inquisitiveness, the team made further research in cave 12 (where the chunk of clay plaster with Vegetal remains were found) to understand if presence of Hemp as an additive showed any specific changes in the interiors.
A comparative analysis of temperature and relative humidity data for a month, of both outside and inside the cave revealed that there was not much of a fluctuation inside the cave, where as the temperature outside showed a wide range of difference in both day and nighttime temperature reading.
Owing to the demographic location, the caves are constantly exposed to a variety of micro climatic condition and microbial degradation, and specially during rainy season insect infestation is a common sight but there were none in cave 12, the scientists also found out that apart from insulation and anti microbial activity, the construction workers of that era used hemp for increasing life span and strength of the lime plaster binder mix.
Remarkably, the level of noise inside cave 12 was much lower than other caves and the surrounding areas. Dr MM Singh concluded that “It appears that properties of hemp fibre such as the ability to regulate humidity inside the cave, pest resistance, fire-retardant, non-toxicity, high vapour permeability, hygroscopic properties, etc. were known to the inhabitants of Ellora in the 6th century AD.”
Their entire find was very much congruent with factual conclusions of present day hemp building experts of Europe, USA, Australia and other countries where currently Industrial hemp enjoys a legal status unlike India, where the law fails to distinguish between Industrial hemp and medicinal cannabis, although does mentions its industrial and medicinal use.
India has always surprised the world with its history and rich culture but when it comes to technological advancement and use of sustainable means in Ancient period , much has been debated, like the construction of Adams Bridge to Sri Lanka or the use of spacecraft’s or vimana without using fossil fuels, not much evidence has been garnered. But, this latest discovery of hemp in the plasters of a 6th century site does give an unbiased evidence that people of that era did know of sustainable ways of construction and most importantly the use of Hemp was not alien or limited to recreational or medicinal purposes only!!
For details on the research paper, please visit – http://www.currentscience.ac.in/Volumes/110/05/0884.pdf