OTTO WILHELM THOMÉ, FLORA VON DEUTSCHLAND, ÖSTERREICH UND DER SCHWEIZ (GERA, 1885); PUBLIC DOMAIN, VIA WIKIMEDIA COMMONS
Organic chemistry has opened a new range of research opportunities for archaeology. Among the latest approaches is Organic Residue Analysis (ORA), which examines organic remains. This method has grown from occasional experimental projects to a key part of scientific archaeological investigation. When integrated with archaeological, botanical, chemical, and anthropological histories, ORA can significantly improve our knowledge of the past. To see how ORA contributes to a holistic understanding of historical uses of psychoactive substances, we will look back at more than 15 years of research on the opium poppy.
Humans have a long relationship with the opium poppy (Papaver somniferum L.).1 The plant has four-petaled flowers and a capsule-like fruit, which produces many seeds inside and a white juice from the outer skin that contains numerous pharmacologically active chemical compounds. These features make opium poppy a multipurpose plant. As a food source, poppy seeds are a significant source of nutrition, largely due to their high oil content, which has a long shelf life and is slow drying. Several different types of poppy were known by the first century AD, as were their medicinal properties and potential dangers.
Poppy products may have served as ingredients in various types of valued substances in antiquity, such as substances that improved health (e.g., medicines or herbal infusions) or products that were cosmetic or hygienic in nature (e.g., perfumes, scented oils, and salves to the hair or skin). The white juice contains more than 40 alkaloids—bitter chemical compounds with various effects in humans, of which morphine is the most abundant. Together, these compounds make opium highly addictive.
Determining how opium was consumed is important for evaluating archaeological evidence. For example, a popular theory that opium was distributed in small juglets from Cyprus would require opium being dissolved in a liquid (e.g., wine or oil). However, some evidence from Cyprus and Crete also suggests smoking apparatuses, such as the so-called ivory opium pipe and the cylindrical vessel from the temple at Kition used for inhalation. Although the preparation and consumption of elite substances is likely for these and other contexts, the method of consumption, whether smoking through direct inhalation or drinking, must be demonstrated. Both smoking and drinking have multiple references in the region, and ORA evidence further supports the existence of a range of consumption practices in the Mediterranean.
Other types of ancient evidence for the opium poppy may include visible or invisible plant remains (e.g., seeds, capsules, pollen, and phytoliths), literary references (e.g., medical recipes), and artistic depictions, suggesting a knowledge of or symbolic association with the opium poppy’s psychoactive and sleep-inducing properties.
COURTESY ZVI LEDERMAN, TEL BETH-SHEMESH EXCAVATIONS
To investigate the ancient use of opium, we used ORA on samples collected from three Cypriot Base Ring juglets recently excavated from a secure 14th-century BC context at Tel Beth-Shemesh in Israel. Here is how we learned what these vessels originally contained. First, we obtained samples by scraping the unwashed interiors of the jugs. Then remaining organic compounds were extracted from the samples by heating the ground ceramic material in a mixture of solvents, including ethanol and methanol, for three hours. The resulting liquefied sample, filtered and concentrated under a steady flow of nitrogen gas, was then analyzed with a gas chromatograph-mass spectrometer, which allows for the separation and identification of different organic compounds (e.g., lipids, alkaloids, and essential oils). Finally, we compared the detected chemical compounds from our samples with those identified in reference samples.
Against the original presumption, this analysis demonstrated that the three vessels from Beth-Shemesh did not contain opium. Instead, a range of aromatic mixtures were identified that included a series of plants (e.g., mint, wormwood, sage, and hyssop) known for their use in medicines and perfumes.2
Considered together with more Base Ring juglets from Cyprus that similarly tested negative for opium, this analysis certainly casts doubt on the popular idea that the Cypriot Base Ring juglets—supposedly shaped like inverted poppy seed pods to advertise their contents—were specifically designed for the transport of opium across the eastern Mediterranean. Nevertheless, other studies suggest the sleep-inducing properties of poppies were known. One example is the identification of the alkaloid noscapine in a fragment of a spouted vessel from the Middle Bronze Age village site of Politiko Troullia in Cyprus. Such vessels are interpreted as infant feeding bottles, and the presence of poppy residue in such a bottle points to the practice of giving children an infusion from a dried poppy capsule to help them sleep—a practice that is mentioned (and cautioned against) in both ancient texts and more recent history.
There is still much that we do not know, and researchers need to ask questions about the cultural and historical settings in which different substances were used. What historical information do we have suggesting the use of a particular substance? What physical evidence is there to support this information? In what instances is ORA feasible, appropriate, and necessary? Will the use of ORA provide answers that other types of evidence cannot?
Our experience shows the best ORA results come from visible remains that have been preserved in complete vessels under extraordinary circumstances. However, this frequently is not the case, as many samples involve residues of organic products that have long disappeared and absorbed into the walls of ceramic vessels. Collecting samples from such vessels requires scraping their interiors or destructively analyzing of sherds. Unfortunately, modern treatment can destroy or contaminate ancient organic material. Complete vessels are often washed in acidic mixtures to clean exteriors, but this destroys absorbed organic residues. Likewise, sherds that were glued together or labeled with sharpies and stored in plastic bags have a high level of contamination. Knowing a sample’s history is thus important, as is integrating the resulting data with archaeological, botanical, and anthropological evidence.
Organic chemistry has opened a new range of research opportunities for archaeology. Among the latest approaches is Organic Residue Analysis (ORA), which examines organic remains. This method has grown from occasional experimental projects to a key part of scientific archaeological investigation. When integrated with archaeological, botanical, chemical, and anthropological histories, ORA can significantly improve our knowledge of the past. To see how ORA contributes to a holistic understanding of historical uses of psychoactive substances, we will look back at more than 15 years of research on the opium poppy. Humans have a long relationship with the opium poppy (Papaver somniferum […]
