The chemical examination of Ngai camphor, performed by Plowman,[1915] under the direction of Prof. Attfield, has proved that it has the composition C₁₀H₁₈O, like Borneo camphor. But the two substances differ in optical properties,[1916] an alcoholic solution of Ngai camphor being levogyre in about the same degree that one of Borneo camphor is dextrogyre. By boiling nitric acid, Borneo camphor is transformed into common (dextrogyre) camphor, whereas Ngai camphor affords a similar yet levogyre camphor, in all probability identical with the stearoptene of Chrysanthemum Parthenium Pers.
As Ngai camphor is about ten times the price of Formosa camphor, it never finds its way to Europe as an article of trade. In China it is consumed partly in medicine and partly in perfuming the fine kinds of Chinese ink. The export of this camphor by sea from Canton is valued at about £3,000 a year; it is also exported from Kiung-chow, in the island of Hainan.
CORTEX CINNAMOMI.
Cortex Cinnamomi Zeylanici; Cinnamon; F. Cannelle de Ceylan; G. Zimmt, Ceylon Zimmt, Kaneel.
Botanical Origin—Cinnamomum zeylanicum Breyne,—a small evergreen tree, richly clothed with beautiful, shining leaves usually somewhat glaucous beneath, and having panicles of greenish flowers of disagreeable odour.
It is a native of Ceylon, where, according to Thwaites, it is generally distributed through the forests up to an elevation of 3,000 feet, and one variety even to 8,000 feet. It is exceedingly variable in stature, and in the outline, size and consistence of the leaf; and several of the extreme forms are very unlike one another and have received specific names. But there are also numerous intermediate forms; and in a large suite of specimens, many occur of which it is impossible to determine whether they should be referred to this species or to that. Thwaites[1917] is of opinion that some still admitted species, as C. obtusifolium Nees and C. iners Reinw., will prove on further investigation to be mere forms of C. zeylanicum.
Beddome,[1918] Conservator of Forests in Madras, remarks that in the moist forests of South-western India there are 7 or 8 well-marked varieties which might easily be regarded as so many distinct species, but for the fact that they are so connected inter se by intermediate forms, that it is impossible to find constant characters worthy of specific distinction. They grow from the sea-level up to the highest elevations, and, as Beddome thinks, owe their differences chiefly to local circumstances, so that he is disposed to class them simply as forms of C. zeylanicum.
History—(For that of the essential oil of cinnamon see page 526). Cinnamon was held in high esteem in the most remote times of history. In the words of the learned Dr. Vincent, Dean of Westminster,[1919] it seems to have been the first spice sought after in all oriental voyages. Both cinnamon and cassia are mentioned as precious odoriferous substances in the Mosaic writings and in the Biblical books of Psalms, Proverbs, Canticles, Ezekiel and Revelations, also by Theophrastus, Herodotus, Galen, Dioscorides, Pliny, Strabo and many other writers of antiquity: and from the accounts which have thus come down to us, there appears reason for believing that the spices referred to were nearly the same as those of the present day. That cinnamon and cassia were extremely analogous, is proved by the remark of Galen, that the finest cassia differs so little from the lowest quality of cinnamon, that the first may be substituted for the second, provided a double weight of it be used.
It is also evident that both were regarded as among the most costly of aromatics, for the offering made by Seleucus II. Callinicus, king of Syria, and his brother Antiochus Hierax, to the temple of Apollo at Miletus, b.c. 243, consisting chiefly of vessels of gold and silver, and olibanum, myrrh (σμύρνη), costus (page 382), included also two pounds of Cassia (κασία), and the same quantity of Cinnamon (κιννάμωμον).[1920]
In connexion with this subject there is one remarkable fact to be noticed, which is that none of the cinnamon of the ancients was obtained from Ceylon. “In the pages of no author,” says Tennent,[1921] “European or Asiatic, from the earliest ages to the close of the thirteenth century, is there the remotest allusion to cinnamon as an indigenous production, or even as an article of commerce in Ceylon.” Nor do the annuals of the Chinese, between whom and the inhabitants of Ceylon, from the 4th to the 8th centuries, there was frequent intercourse and exchange of commodities, name Cinnamon as one of the productions of the island. The Sacred Books and other ancient records of the Singhalese are also completely silent on this point.