Compound quills, measuring 42 ins. long (just over 1 m), are sorted into grades according to the thickness of the hark. Three main qualities are exported: the ‘Tine’ or ‘Continental’ grades, the intermediate `Mexican’ grades, and the ‘Hamburg’ grades.

In the USA, spice millers cut selected pieces of the three types of cassia bark into short lengths for sale as ‘whole cinnamon’. The great bulk of the cassias imported is ground to produce ‘ground cassia- cinnamon’. The various kinds of cassia bark are different in flavour and degree of aroma, but all are agreeable, fragrant and aromatic. Saigon cassia is generally acknowledged to possess the fullest and finest flavour and it is the preferred type in the USA. The various types are ground separately or blended to meet the needs of the bakery and food- processing industries, being used directly in the ground form or for oleoresin extraction. Ground cassias are sold for domestic culinary use, usually without distinction as to type, under the label of ‘cassia- cinnamon’.

Perhaps the finest thing about the dahlia is its internationalism, for the varieties grown in this country originated all over the world. This is probably equally true of nearly every other dahlia growing country. This means of course that there are an enormous number of varieties available, but has also meant that the standards of quality have risen greatly over the years.

In addition the committee is responsible both for the selection of dahlias for trial at the Royal Horticultural Societies Gardens at Wisley and for the judging of such varieties. It advises both societies on matters of mutual interest, and is concerned with maintaining good relationship between the two societies and other kindred bodies.

It also sponsors trials of dahlias, although on a somewhat different basis from that of the Wisley Trials as the Association is mainly concerned with commercial potential. For this purpose the trials seem reasonably suitable, but are not quite so helpful to the average amateur as the more strictly run Wisley trials. An award from the B.D.G.A. is unlikely to be of such high value as a selling point as an award at Wisley, a point that is recognised fully by the members of the association.

The oleoresins are prepared mainly by the flavour industries of Western Europe and North America; and they have similar applications to the ground spices in the flavouring of processed foods.

Cassia buds which enter commerce are, as already stated, the dried unripe fruits contained within the calyx cup. They are smooth and greyish-brown or reddish-brown in colour, 6-10 mm long and about 5 mm in diameter at the tip; the calyx is hard and wrinkled. They have a spicy cinnamon-like odour and a warm sweet pungent flavour. They are used in sweet pickles.

The harvested bark is thus of two kinds – rectangular slabs and quills, the latter being obtained mainly from the smaller branches. The unrolled slabs, which are more valuable, undergo complicated traditional methods of curing in different parts of Vietnam. Most of these method involve alternate washing and drying, with minor fermentation in heaps. Finally, the slabs are tied around thick bamboo for drying and so assume a broadly curved appearance. The thinner bark from the smaller branches is prepared as quills by scraping and drying in the usually way.

Chinese cassia is cultivated mainly in the provinces of Kwangsi and Kwangtung in southern China. It was once harvested from wild bushes growing in the mountains in addition to cultivated bushes, but is now restricted to the latter.

They should, however, be planted close enough to encourage the formation of a tall straight trunk with as few branches as possible. The best spacing is about 1 m between plants. The use of Tephrosia candida (Roxb.) DC. as a nurse crop has been recommended in Sumatra. This may be sown six months ahead of the cassia in rows about 1 m apart and the young cassia trees are planted in clearings about 60-70 cm in diameter made in the Tephrosia, which later can be cut back to 15 cm and spread between the rows.

The perianth, which is pale yellow in colour, is deeply divided into 6 oblong blunt lobes. There are 9 functional stamens and 3 staminodes. The anthers are four-celled, opening by 4 valves or flaps. The central superior pistol has an oval ovary and a stout, short style. The fruits are smaller than those of C. verum and are black, pulpy, aromatic, elliptic drupes with a single seed borne in the cup of the calyx lobes. The fruits are avidly eaten by birds which disperse the seeds.

The dried inner hark of C. verum contains a steam-volatile oil, fixed oil, tannin, resin, proteins, cellulose, pentosans, mucilage, starch, calcium oxalate and mineral elements. The relative abundance of these components can vary somewhat according to the geographical origin of the spice, its quality and the duration of storage.

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.

In comparison to Sri Lankan bark oil, the Seychelles product was found to he poorer in odour and flavour and less soluble in alcohol, and it was not possible to produce a Seychelles cinnamon bark oil which could satisfy the requirements of the British Pharmacopoeia.

The characteristic organoleptic properties of the spice and its oleoresin are determined by the composition of their steam-volatile (essential) oils. The small amount of coumarin present also influences the flavour but other non-steam-volatile constituents appear to be unimportant. Detailed analyses of the composition of the natural steam-volatile oil occurring in the spice have not been reported, and its composition must be inferred from the information available on the distilled bark oil. The latter, however, contains some artefacts produced by the distillation procedure and is less esteemed than the spice and oleoresin in organoleptic terms.