As regards Western Asia and Europe, we find a root called ῤᾶ or ῤῆον, mentioned by Dioscorides as brought from beyond the Bosphorus. The same drug is alluded to in the fourth century by Ammianus Marcellinus,[1805] who states that it takes its name from the river Rha (the modern Volga), on whose banks it grows. Pliny describes a root termed Rhacoma, which when pounded yielded a colour like that of wine but inclining to saffron, and was brought from beyond Pontus.
The drug thus described is usually regarded as rhubarb, or at least as the root of some species of Rheum, but whether produced in the regions of the Euxine (Pontus), or merely received thence from remoter countries, is a question that cannot be solved.
It is however certain that the name Radix pontica or Rha ponticum, used by Scribonius Largus[1806] and Celsus,[1807] was applied in allusion to the region whence the drug was received. Lassen has shown that trading caravans from Shensi in Northern China arrived at Bokhara as early as the year 114 b.c. Goods thus transported might reach Europe either by way of the Black Sea, or by conveyance down the Indus to the ancient port of Barbarike. Vincent suggests[1808] that the rha imported by the first route would naturally be termed rha-ponticum, while that brought by the second might be called rha-barbarum.
We are not prepared to accept this plausible hypothesis. It receives no support from the author of the Periplus of the Erythrean Sea (circa a.d. 64), whose list of the exports of Barbarike[1809] does not include rhubarb; nor is rhubarb named among the articles on which duty was levied at the Roman custom-house of Alexandria (a.d. 176-180).[1810]
The terms Rheum barbarum vel barbaricum or Reu barbarum occur in the writings of Alexander Trallianus[1811] about the middle of the 6th century, and in those of Benedictus Crispus,[1812] archbishop of Milan, and Isidore[1813] of Seville, who both flourished in the 7th century. Among the Arabian writers on medicine, the younger Mesue, in the early part of the 11th century, mentions the rhubarb of China as superior to the Barbaric or Turkish.[1814] Constantinus Africanus[1815] about the same period speaks of Indian and Pontic Rheum, the former of which he declares to be preferable. In 1154 the celebrated Arabian geographer Edrisi[1816] mentions rhubarb as a product of China, growing in the mountains of Buthink—probably the environs of north-eastern Tibet near Lake Tengri Nor (or Bathang in Western Szechuen?).
Rhubarb in the 12th century was probably imported from India, as we may infer from the tariff of duties levied at the port of Acon in Syria, in which document[1817] it is enumerated along with many Indian drugs. A similar list of a.d. 1271, relating to Barcelona, mentions Ruibarbo.[1818] In a statute of the city of Pisa called the Breve Fundacariorum, dating 1305, rhubarb (ribarbari) is classified with commodities of the Levant and India.[1819]
The first and almost the only European who has visited the rhubarb-yielding countries of China is the famous Venetian traveller, Marco Polo,[1820] who speaking of the province of Tangut says—“ ... et par toutes les montagnes de ces provinces se treuve le reobarbe en grant habondance. Et illec l’achatent les marchans et le portent par le monde.”
A sketch of the history of rhubarb would be incomplete without some reference to the various routes by which the drug has been conveyed to Europe from the western provinces of the Chinese Empire, and which have given rise to the familiar designations of Russian, Turkey and China Rhubarb.[1821]
The first route is that over the barren steppes of Central Asia by Yarkand, Kashgar, Turkestan, and the Caspian to Russia; the second by the Indus or the Persian Gulf to the Red Sea and Alexandria, or by Persia to Syria and Asia Minor; and the third by way of Canton, the only port of the Chinese Empire which, previous to the year 1842, held direct communication with Europe.
In 1653 China first permitted Russia to trade on her actual frontiers. The traffic in Chinese goods was thereupon diverted from the line of the Caspian and Black Sea further north, taking its way from Tangut across the steppes of the high Gobi, and through Siberia by Tobolsk to Moscow. Thus it is mentioned in 1719 that Urga on the north edge of the Gobi desert was the principal depôt for rhubarb. From the earliest times, Bucharian merchants appear to have been agents on this traffic, the producers of the drug never concerning themselves about its export.