Cinnamon bark oil is a pale-yellow liquid possessing the delicate aroma of the spice and a sweet and pungent taste. Its major constituent is cinnamaldehyde, but other components present in minor or trace quantities impart the characteristic odour and flavour which distinguishes this oil from other Cinnamomum bark oils. These components include eugenol, eugenol acetate and small amounts of aldehydes, ketones, alcohols, esters and terpenes. Arctander (1960) attributes the powerful characteristic notes of good oils to the presence of methyl-namylketone together with other, aldehydes and ketones. However, detailed studies of the relationship of the oil composition to its organoleptic properties have not been reported in the literature.

The variation in the properties of the spice according to its grading have been described in the `Products and end-uses’ section, and the current standards are given in the ‘Standard specifications’ section.

Cinnamaldehyde was identified as the major constituent of Sri Lankan cinnamon bark oil by Dumas and Peligot (1834, 1835), and more detailed analyses of the oil composition were undertaken later by chemists of the Schimmel Co. (1892c) and by Walbaum and Huthig (1902).

Cinnamon is the dried bark of Cinnamomum verum (syn. C. zeylanicum). It is indigenous in Sri Lanka, which still produces the largest quantity and best quality, mainly in the form of quills. The Seychelles is the second largest producer, the exports being mainly in the form of rough bark. Small exports are made from the Malagasy Republic.

The spice is used in baking and pickling; it has also a limited use in pharmaceutical products and in incense. Like many other spices, cinnamon was regarded as having aphrodisiac properties.

The Chalais, the caste to which the peeling and preparation of cinnamon bark is now restricted in Ceylon, are said to have emigrated from India in the thirteenth century.

Cinnamon was one of the first spices to be sought after by most fifteenth- and sixteenth-century explorations. It was one of the spices which sent Columbus to the west to discover the eastern spice islands. In his diary for 4 November 1492, we read that, following a reconnaissance of the north coast of Cuba, PinzOn, captain of the Pinto, brought Columbus two pieces of bark, claiming that he had found cinnamon. They were probably Capella winterana (L.) Gaertn., which is still known in the West Indies as wild cinnamon. It was the same search for spices which led Vasco da Gama to round the Cape of Good Hope and reach the Malabar coast of India in 1498.

Incidentally, do please note that whatever form of heating is used, the heating elements should be under the bench; this concentrates the heat where it is most required and, in the case of oil stoves, will keep the pathway free from obstructions. If necessary the soil under the benches should be excavated to allow the heaters to be set into position.

On the other hand, the temperature is automatically controlled by a thermostat, so that very little attention is required, and certainly no stoking, which can be a somewhat unpleasant task on a cold night. Of all the various electrical systems available probably the most useful is that based on a water circulatory system, as there is some small reserve of heat should the current fail and, in addition, the drying effect on the air in the greenhouse is not so marked as in the normal radiant type.

As a compromise soil warming cables can be used to heat the tuber and propagating beds. Space heating will still be required as these cables do not cause any appreciable rise in the air temperature, but this need only be sufficient to maintain a minimum of say 4o to 45 F. Even if electrical space heating is used, with the thermostat set about these figures, the cost of heating will not be unduly high. Alternatively, an oil heater may be used to supply the necessary space heating.

If a spare frame is not available, it is possible to use temporary structures made from loose bricks, breeze blocks, and so on, or even to utilise an open part in the garden without protection, say along the outside edge of the dahlia plot, but in such cases it is probably advisable to bury the pots completely, and also to give each plant a light cane.

The National Show, held each year in the two Royal Horticultural Society Halls, is one of the finest in the world at which the amateur predominates in the competitive classes. The trade exhibits also bear favourable comparison with those of other countries.

The usual potting mixtures are quite suitable, preferably containing some nourishment; John Innes No. 2 is particularly good.

Among its activities it makes available all known information on the dahlia, gives advice to members and affiliated societies, maintains a national register of judges and lecturers and co-operates with similar societies in other countries. Covering, as it does, an extremely wide area, there is a Northern Committee, which looks after the main interests of members north of the Trent, organising at least one provincial show, and staffing bureaux at the bigger Northern shows.

Camphor oil is obtained by distilling the wood or leaves of Cinnamomum camphora (L.) Presl, which is a native of China, Japan and Taiwan, the last island producing the greatest amount. C. camphora can be distinguished from the other species of Cinnamomum mentioned above by the leaves being pinninerved, whereas the others have three to five distinct nerves from the base of the leaves proceeding towards the tip; camphor also has stout dormant buds. A large proportion of the world’s camphor is now produced synthetically from pinenc, a turpentine derivative, or from coal tar. Camphor is used in the manufacture of celluloid, in disinfectants and chemical preparations, and has a wide range of medicinal uses. Safrole, produced from the residual oil after camphor extraction, is used in soap and perfume manufacture.

Other species of Cinnamotnum, whose barks are used as spices or in medicine include: C. culilawan (Roxb.) Presl from the Moluccas; C. iners Reinw., which occurs from western India and Tenasserim (Burma) to Malaysia, Indonesia and the Philippines; C. javanicum Bl. in Malaysia and Indonesia; C. part henoxylon (Jack) Nees in Tenasserim and western Malesia; and C. sintoc Bl. in Java. All the binomials and authorities in this section are taken from Kostermans.

Long stemmed blooms of Dahlia can be supported with pad of soft material used to support weak necked blooms-not required for stronger stemmed varieties. Stem and cane should be tied at not less than two places above and two below the first pair of leaves, ignoring the single leaves which occasionally appear.

If a light, thin cane is secured to the stem, extending from just below the bloom to a point about 1 foot below the first pair of leaves, the danger of breakage is negligible. Make one tie just below the bloom, and at least one below the first joint.

This tip is particularly useful with varieties with rather soft footstalks as these often bend beneath the weight of the developing bloom, although the stem usually stiffens once the bloom reaches maturity. In this case it is best to cut with the cane still tied to the stern, and to leave the cane in position until the bloom has been vased up and has had opportunity to become fully charged with water.

The nutmeg tree, Myristica fragrans, is unique among the spice plants as it produces two separate and distinct products – the nutmeg which is the kernel of the seed and the mace which is the dried aril that surrounds the single seed within the fruit. It is a spreading evergreen tree, usually dioecious, which is native to the Moluccas in the East Indian Archipelago, belonging to the small primitive family Myristicaceae. Nutmegs reached Europe after cloves.

By 1650 the order had become fairly effective. Most writers comment that the scheme was thwarted by fruit pigeons which swallowed the seeds and voided them on neighbouring islands. The original source of this statement, which has been faithfully copied, is hard to identify, but the story, like the seeds, is rather hard to swallow. It is possible that the spice occurred in regions of the islands unknown to the Dutch, and there was a brisk trade in spices by the natives with Mindanao and Kedah.

Although perhaps not entirely a matter proper to a treatise on dahlias, the period of a dahlia’s life in which it inhabits a greenhouse or frame plays such an, important part that it seems advisable to digress a little.

It may sound strange that so much stress is placed on keeping temperatures down, but whereas it is not difficult to maintain a reasonable temperature even on a cold clay by a variety of means, it is most difficult to prevent the temperature soaring on a sunny clay in a small house. Cuttings soon flag if exposed to excessive dry heat, and, once having flagged, are not only slow in recovering, but arc also more likely to damp off and much more likely to take a long while to strike. So the maxim is-shade!

Usually a water circulating heating system will give too much heat for a small house, while most alternative systems are either expensive or somewhat unsatisfactory in one way or another.

In the course of transporting, bleaching and grading the quills, some breakage takes place; the broken lengths and fragments of quills of all grades are bulked, packed in bales of 100 lb (45 kg) and are sold as quillings.

Feat herings grade consists of the inner bark of twigs and twisted shoots which will not give straight quills of normal length. They are thus also genuine cinnamon but they often contain a proportion of chips. Like the quillings, featherings are exported in bales of 100 lb (45 kg).

These oleoresins differ in the quality of their flavour and odour and in the content and composition of volatile oil and, therefore, in their flavour strength. Volatile-oil contents of commercial ‘cinnamon oleoresin’ have been reported to range from 16 to 60 per cent. The details of their preparation are more than usually meagre but Ceylon cinnamon yields 10 to 12 per cent of oleoresin with ethanol and 2.5 to 4.3 per cent with benzene, and according to Salzer Chinese cassia (from C.cassia) yields an oleoresin containing about 66 per cent volatile oil.

In Sri Lanka, cinnamon leaf oil is generally produced by steam distillation of dried leaves on rather simple, but nevertheless effective, equipment. At one time, two types of leaf oil were produced which possessed differing properties.

In the Seychelles, cinnamon leaf oil is produced by water – steam distillation (with cohobation) of leaves which are hand-stripped from shoots cut for bark production. Collection of leaves takes place at intervals of 18 to 20 months during January to September. The young leaves are unsuitable for distillation during the ‘flushing period’ which occurs in the rainy season from October to December. The average yield of leaves is 1.8 tonnes per hectare.

Leaves alone give a lower yield than a mixture of leaves plus twigs, and the best quality oil is obtained from material harvested in the summer and autumn from trees which are 5 to 7 years old.