Traces of hemp have already been found in ancient Chinese tombs dating back to about six thousand years ago: according to archaeologists, the decorations on some terracotta vases were made by pressing hemp strings onto fresh clay. Other important information on the importance of hemp in China came from more recent burials discovered in the 1970s and dating back to one thousand BC: the inhabitants of ancient China had learned to weave and spin hemp, freeing themselves from their dependence on animal skins, and making clothes and shoes, thanks also to having learned to recognize that male plants produced a better fiber, while female plants produced edible seeds.
The breakthrough has now come from analyses carried out on ceramics found in eight tombs in the Zoroastrian cemetery of Jirzankal, in the eastern part of the country, as the researchers explain in the journal Science Advances. The analysis of the stones of the different wooden braziers found in the ancient burials showed that the cannabis plants used had high levels of tetracannabinol (THC, its most powerful psychoactive compound). This would indicate, according to the researchers, that the people of that time were aware of the psychoactive properties of the plant and that they knew how to work with the different varieties of plants, selecting those with more THC.
To understand if the braziers had a specific ritual function, the researchers extracted organic material from the fragments of burned wood and stones, analyzing them with mass spectrography. To their great surprise, the results showed the exact mixture of cannabis, with a high amount of tetracannabinol. Probably, the researchers hypothesize, it was smoked during burial ceremonies, perhaps to communicate with the deities or the deceased.
"These findings support the hypothesis that cannabis plants were first used for their psychoactive substances in the mountainous regions of eastern Central Asia, and from there spread to other regions of the world," Boivin comments. The region where they were found, the Pamirs, so remote today, was at that time along the first Silk Road. According to archaeobotanist Robert Spengler, the Silk Road trade routes functioned like the spokes of a bicycle wheel, with Central Asia at the center of the world.
