Everything new is well forgotten old, or „that awkward moment“ when it becomes clear that the knowledge of the ancient builders was 1,500 years ahead of modern know-how.
Indian scientists studied the composition of the plaster in one of the cave temples of Ellora in an attempt to solve the mystery of the striking conservation of ancient frescoes. Ellora is a famous temple complex of V-IX century in the Indian state of Maharashtra, it is a grand monument on the UNESCO World Heritage Site list and a marvel of architecture – the 34 temples were carved by the ancient builders in basaltic rocks.
Besides historical and architectural value, the temples of Ellora have become a symbol of religious harmony in its time – in the southern part of the complex there are 12 Buddhist temples, in the central part – 17 Hindu, in the north – 5 Jain temples.
All temples are numbered in accordance with the estimated chronology of the construction. The Buddhist temple №12, or Tin Tal, was chosen for the study. It was built between the V and VII century, together with the rest of the Buddhist part of the complex.
One of the authors of the study – the archeo-chemist Manager Rajdeo Singh, has long been engaged in the conservation and restoration of these monuments. He noticed the good preservation of the frescoes in temple №12, compared to the others. Samples taken from the plaster showed unexpected result – in the foundation of the mixture for plastering the walls vegetation fibers were discovered – namely cannabis.
The botany professor Milind M. Sardesai also participated in the study. The ancient plaster was studied with all available modern means. All results suggest that the classical mixture of clay and lime contained 10% cannabis fibers and that it was the cannabis that had given the ordinary plaster almost supernatural properties.
Sardesai collected samples of cannabis around Jalil, near Aurangabad, in the vicinity of Delhi. „The analysis showed gull correspondence of the modern samples with the cannabis found in the composition of the ancient material. The samples from the cave temple at Ellora contained 10% Cannabis, Cannabis Sativa, mixed with sand or clay. This explains the also lack of traces of insect activity in Elora,“ said Singh, quoted by The Times of India.
It’s not a coincidence that Singh mentioned insects. For a long time he worked in Ajanta – it is another temple complex, near the Ellora cave temples, but older. The temples of Ajanta were created in the II century and no cannabis was used in building them. The result – „Insects have damaged at least 25% of the murals in Ajanta,“ says Singh.
But the ability of cannabis to repel harmful insects is not the only „superpower“ of this plant. „Cannabis fibers are stronger and more durable than other vegetable fibers. Furthermore, resins contained in cannabis may have played a role of effectively binding plaster, increasing the quality of the mixture of clay and lime,“ Sardesai says for Discovery News.
According to scientists the cannabis in the plaster „is not only a natural insecticide and pesticide, but also stores heat excellently, it is moisture resistant and is able to regulate the humidity level, it is not toxic, it has fire is and has sound insulation properties (it is able to absorb up to 90% natural sound).
Paradox: today this technology is called an innovation, the building material itself – hempcrete (from “hemp” – cannabis and “concrete” – cement). The unique properties of the cannabis became known to modern builders thanks to a similar historical study conducted a few years ago in India and in France.
French scientists have found traces of cannabis in construction materials of the same age as and temples in Ellora – VI century. Since then, this simple and effective technology has been literally forgotten for a millennium and a half and was revived only in recent years.
„Ellora is a visual evidence that only 10% of cannabis fibers mixed with clay and lime, were able to preserve and protect the walls from damage for 1500 years,“ says Singh.