Jarrah is a very close-grained Australian hardwood used in building and furniture making. Jarrah is so close grained that normal wood primers will not penetrate it, and instead it needs to be treated with a thin aluminium or synthetic primer prior to painting. Research Jarrah
The cleg (clegg, breeze-fly, gad-fly) is a name applied to the members of the insect family Tabanidae, which are flies furnished with a lancet-like proboscis, of powerful flight, and a habit of sucking blood. It is only the female which sucks blood, and in some examples - such as the Hadrus lepidotus of Brazil - they may inflict wounds which bleed very freely. The common cleg (Tabanus bovinus) is a large insect resembling a bee which produces a deep hum which panics horses and cattle. It also attacks man, and its hard proboscis can penetrate even thick clothing. Research Cleg
Cowitch, or cowage (named from the Hindu kiwanch) is the hairs of the pods of leguminous plants of the genus Mucuna, natives of the East and West Indies. The pod is covered with a thick coating of short, stiff, brittle, brown hairs, the points of which are finely serrated. They easily penetrate the skin, and produce an intolerable itching. They were formerly employed medicinally (being taken in honey or syrup) as a mechanical vermifuge. Research Cowitch
Seed Beetles or bean weevils is the popular name for insects of the family Bruchidae (formerly Lariidae), order Coleoptera. They are mostly small, compact beetles measuring less than 5 mm in length and generally with the head produced into a short rostrum. The larvae develop in the fruits of leguminous plants, the adult female laying her eggs on pods ripening in the fields. The larvae hatch with well-developed legs, penetrate the pod, bore a hole into the seed and develop in that. The larvae first moult into a different legless larvae, before pupating and emerging from the harvested seeds as an adult beetle. Research Seed Beetles
Tobacco is the name given to the leaves of those varieties of the Nicotiana which are prepared in different forms for use as a narcotic. It is generally manufactured for smoking, but also for chewing and as snuth.
The word tobacco is probably derived from tobaco, the name given to a peculiar Y-shaped instrument used by the old inhabitants of the island of Santo Domingo for inhaling tobacco-smoke through the nostrils. Other authorities claim that the name of the herb is derived from the Mexican word tabacco. Columbus and his party made the earliest European reference to tobacco on their return from the voyage to Cuba in 1492. The tobacco plant was first brought to Europe in 1558 by Francisco Fernandes, a Spanish physician. The wonderful healing properties which the plant was supposed to possess caused the habit of smoking and snuff-taking to spread with great rapidity over almost the whole of Europe. Jean Nicot, French ambassador to Portugal, who gives his name to the genusNicotiana, sent a present of tobacco seeds to Catherine de'Medici, and she initiated in France the snuff-taking habit as a cure for headache. This habit soon spread to Scotland and Ireland, where it remained popular long after the smoking habit had become established in England.
The smoking of tobacco was really started by English example. In 1586, Ralph Lane, the first governor of Virginia, and Sir Francis Drake brought smoking materials and implements to Sir Walter Raleigh, who very rapidly popularised the custom.
Most of the tobacco used in the 17th and 18th centuries was grown in Virginia by English colonists, whose industry was carefully protected by laws prohibiting the production of tobacco in the British Isles.
There are about 50 species of Nicotiana, most of them indigenous to America. Of these, three varieties are in general use by smokers: (1) Nicotiana tabacum, the Virginian variety, originally derived from the South or Central American seed, and now cultivated in almost all temperate and warmer climates. (2) Nicotianarustica, grown principally in Turkey, Syria, and India. This is milder in flavour, and is principally used for the manufacture of cigarettes. It burns too quickly for a pipe tobacco. (3) Nicotiana Persica, or Persian tobacco, which is good for pipe tobacco, but not sufficiently uniform for the manufacture of cigars.
The tobacco plant is a coarse, rank-growing annual. Its stem is simple and unbranched, and grows to a height of about two meters, terminating in a bunch of yellow or rose-coloured flowers. The East Indian variety is slightly different, producing a green tobacco from a smaller plant. It is derived from the Mexican seed, and is also cultivated in Southern Germany and Hungary.
The tobacco plant can be cultivated in every part of the world, but with widely varying measures of success. It is grown in British gardens for the sake of its flowers. Clayey, moist soils produce tobaccos which are dark brown or reddish in colour when cured. Bright and yellow tobaccos are grown on sandy soils, and the leaf of this variety is thinner. The bright tobacco produced in Virginia and North Carolina is all grown in loose sandy soil with a clay subsoil.
The tobacco seeds are generally sown in nursery beds, and set out later. About 3OOOOO to 4000000 go to the ounce, and this produces about 40,000 plants, for which 50 square yards of nursery bed are sufficient. The seeds are sown at the end of March or beginning of April, in rich, heavy soil which has been carefully prepared and fertilised. The seedlings remain in the nursery from fifty to sixty days, during which time the fields are well tilled and manured. Transplanting is done on a warm, rainy day, and the young plants set in ridges varying from one to four feet in width. Ridges of one to one and a half feet are most usual in Cuba and Sumatra, as the wider ridge produces a leaf which is too coarse for the purpose of cigar-making.
The crop takes another two months until it flowers, and at this stage the buds are pinched off or 'topped', and some of the leaves pruned, so that only a certain number are left to ripen. For cigar-tobacco, from 15 to 20 leaves are left on the plant; for the best smoking tobaccos, 10 to 12 leaves. Plants which have been topped form suckers, and in Florida these are left to produce a second, although inferior, sucker crop.
The leaves take about 35 days to ripen after the plants are topped and pruned. The ripening leaf changes from a dark to a lighter yellowish-green colour, and is often mottled and becomes gummy. The ripe leaf cracks and creases when folded. The lower leaves ripen first, and for the best tobaccos the leaves are picked singly ;
as they ripen. For the bulk of the tobaccos, however, the whole plant is cut when the middle leaves are ripe. Warm, cloudy days are best for cutting, and the plants are not gathered in hot sunshine or when they are wet from rain or dew.
After harvesting the plants are left in the open to wilt, and are then conveyed to the drying-house or ventilating-barn, where they are straddled across tiers of poles and dried in a temperature which is raised to 170° F for four to five days. On damp days the moisture is allowed to penetrate into the drying-house to make the leaves pliable.
The plants are then taken down and stripped, and the leaves sorted into firsts, seconds, and lugs - the name given to the inferior leaves. They are formed into hands containing ten to twelve leaves, and these are left in heaps and fermented at a temperature of about 130° F for from three to four weeks. The heaps are shuffled from time to time, to allow all the leaves to assume a uniform brown tint. This process is called the fermenting or sweetening process. In the non-fermenting processes the leaves are simply sun-cured, or sun-dried, and this tobacco is used chiefly for chewing tobaccos. In the fermenting process the starch and sugar in the leaf are decomposed, but they are retained in the sun-dried process. Lastly, the leaves are packed carefully in hogsheads for shipment.
Tobacco leaf is used for making into various smoking mixtures, roll tobacco, cake or plug, cigars, cigarettes, and snuff. For snuff the leaf requires very careful fermentation during several weeks. It is ground up and flavoured so as to produce the greatest possible amount of free ammonia, free nicotine, and other aromatic scents. Syria produces and manufactures a smoking tobacco which is known as Latakia. It is similar to Turkish-grown tobacco, but differently treated. The plants are not topped. The seeds as well as the leaves are included in the curing, this taking place in the smoke of a fire of evergreen-oak, which gives a black colour and a peculiarly strong flavour to the tobacco.
Tobacco for pipe-smoking is mostly grown in the USA, the chief states being Kentucky, North Carolina, and Virginia. Louisiana grows a dark, almost black, and very strong tobacco known as perique. Cigarette tobaccos are principally imported from Virginia, and Turkish and Egyptian cigarettes are also in great demand. The Egyptian cigarette is made from Turkish leaf, as the cultivation of tobacco in Egypt was prohibited in 1891. The best cigar tobaccos are grown in Cuba. A very good cigar leaf is also produced in Jamaica, Sumatra and North Borneo.
Since the introduction of tobacco into England, it has been subject to continuous legislation and import duties. In the early days a certain quantity of tobacco was grown in England for domestic consumption, and quite a considerable trade was done with Turkey, which, at that time, imported her tobacco supplies from England. Queen Elizabeth imposed a tax of 2d per Ib on imported tobacco. In 1621 James I increased this to 6s. lOd. per Ib.
During the American War of Independence, England's source of supply and the revenue there from were temporarily suspended, and tobacco was again widely planted in England, although the prohibition laws had not been repealed. These laws had never applied to Scotland, and to reimburse themselves for the loss of revenue during the non-importation of American tobacco, the Government purchased the Scotch tobacco crops at the fixed price of 4d. per Ib., thus temporarily creating a Government monopoly in tobacco. The ban on the growing of tobacco in the British Isles, renewed in 1782 in England, and in 1830 in Ireland, was modified later in the 19th century, and tobacco can now be cultivated under licence.
During the late 20th century an American-led ban on tobacco smoking supposedly because of the connection with lung cancer, but more likely under pressure from the pharmaceutical lobby, in public places slowly extended to Britain, with Scotland banning the smoking of tobacco in pubs and clubs in 2005. Research Tobacco
The acrosome is a thin cap of protoplasm encasing the head of a sperm. The acrosome is believed to contain an enzyme, hyaluronidase, that dissolves the coronaradiata, the protective outer coat of the ovum, making sperm penetration easier. The enzyme of the acrosome of one sperm is insufficient to break down the ovummembrane. Therefore, contrary to popular opinion, it takes more than one spermatozoon to produce a baby. Only one sperm, however, will actually penetrate the egg. Research Acrosome
Amoebic dysentery is an illness caused by the pathogen Entamoeba histolytica which is transmitted by the faecal-oral route. Cysts are excreted in the faeces of an infected individual or carrier and ingested through faecally-contaminated food, water, objects, etc. After excystation, the trophozoites penetrate the walls of the large intestines causing ulceration and frequently causing the symptoms of dysentery. Involvement of the liver and other organs may occur if the protozoan invades the blood. Research Amoebic dysentery
Dentine (dentin) is the main substance of the tooth, composing the bulk of the crown and root of the tooth. Dentine is similar in hardness to compact bonetissue, found throughout the skeleton, and features about 30% organictissue. Like the enamel, no cells or vessels penetrate the
dentine, so that damage to the dentine (as in the case of a dental cavity) cannot be repaired. In some teeth, a secondary dentine may form as an accretive patch over damaged or occluded toothtissue, however. Though no cells or vessels penetrate the dentine, small tubules do penetrate into the dentine matrix from the pulp cavity. Within these tubules are housed odontoblasts in a protoplasmic base. These tubules make the dentinal matrix sensitive to contact or temperature changes. Research Dentine
The enamel (substantia adamantina) covers the crown of the tooth and is the hardest known substance in the body. This hardness is necessary to survive the powerful forces exerted on the tooth surface during chewing.
Enamel is composed predominantly by calciumsalts, with less than five percent of its weight being due to organic tissues. Since no cells or vessels penetrate into the enamel, it is not considered living tissue. Because of this, damage to the enamel of a tooth (as in the case of a dental cavity) cannot repair itself.
Meissner's corpuscles are small, nodular structures which penetrate the nerve cells. They contain spiral nerve fibrils which innervate tissues throughout the body, including the epidermis of the hands, fingers, feet, and the mucous membranes of the eyelid and tongue. They are strongly related to the tactile senses. Research Meissner's Corpuscles
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Jarrah
