A spa is a health resort at which natural waters or baths can be taken for therapeutic purposes. The name is derived from the town of Spa in Belgium, one of the oldest watering places. Many forms of natural waters exist, suitable for the treatment of various complaints, but the particular characteristics of the water is not the solefactor which gives a spa its therapeutic efficiency. The spas often provided a period of hygienic living to people who otherwise were deprived of it, and this often proved as beneficial as the waters themselves.
In its narrow, everyday use, vegetable is a word indicating any herb that is cultivated specially for table use in whole or part, such as the turnip (root), cabbage (leaves), broccoli (flowers), peas and beans (fruit). In its widest sense it includes all living things that are not animals - trees, shrubs, herbs, ferns, mosses, seaweeds, fungi, and the microscopic diatoms.
The unit of structure, the cell, is essentially the same in both animals and plants, but the combination of the cells into tissues and organs shows marked differences.
All animals depend for their food upon material originally elaborated by plants. The green plants alone have the power to construct this basic food material from elemental substances, and physiological processes different from those of animal assimilation are rendered necessary. The fungi approach the animals in this respect: they must feed upon material that has already done service as part of the structure of other plants or of animals.
The fine divisions of roots explore the soil in search of water in which are dissolved the salts of sodium, iron, potassium, phosphorus, calcium, sulphur, etc. The hairs with which the rootlets are clothed absorb this fluid by osmosis, and it is passed upward through the long vessels of the wood bundles until it reaches the cells of the leaf. These cells contain green bodies (chloroplasts) in their protoplasm, and it is these that impart the green colour to leaves and soft shoots. In the leaf-skin (epidermis) there are innumerable pores or stomata through which surplus water from the roots is evaporated and through which atmospheric air is admitted to the spaces between the leaf-cells.
The chloroplasts in these cells have the power to utilise solar energy in decomposing the carbon dioxide of the air, and the cells retain the carbon, setting free the oxygen. Water from the roots is broken up also into its elements, hydrogen and oxygen, and with these plus carbonstarch is formed. This, converted into grape sugar, is passed from cell to cell to parts of the plant whore it is needed for the production of new cells, wood, bark, leaves, or fruit. Starch is the material from which are made all the organic substances produced by the plant.
The surplus over present requirements is stored up as reserves in seeds, enlarged roots or stems, bulbs, or tubers for renewed growth or floral display at a later season. Waste products are converted into resins, oils/wax, or alkaloids - many of these being of considerable economic value to man. Part of the water stream from the roots passes by osmosis from cell to cell, where it is necessary in order to keep the protoplasm in an active condition; any insufficiency is followed by a flagging of the tissues, the drooping of leaves and young shoots. In addition to the absorption of carbon by the protoplasts for building purposes, the leaf-cells also take up oxygen from the atmosphere and give off carbon much as animals do.
As the plant respires without lungs and assimilates without digestive organs, so also it can effect movements without a muscular system and react to external stimuli without a nervous system. It is sensitive to light and heat; many plants have distinct night and day positions for their leaves. It responds positively and negatively to the force of gravity, the root going down into the earth and the stem rising into the air. The growing tip of a stem or shoot commonly nutates, i.e. moves from side to side or in a circle or ellipse. The plant can orientate itself, i.e. take up a definite position in regard to the incidence of light or other external stimulus. These movements appear to be controlled largely by alterations in the position of the mobile chloroplasts.
The reproductive process is, in essentials, similar to that of animals, the ovules or seed-eggs in the ovary requiring to be fertilised by male sperms represented by the pollen grains produced in the anthers. The result of such fertilisation is to cause the ovule to develop into an embryo capable of further development under suitable conditions into a plant resembling the parent. Research Vegetable
Nutrition is the strategy adopted by an organism to obtain the chemicals it needs to live, grow, and reproduce. The term is also applied to the science of food, and its effect on human and animal life, health, and disease.
Nutrition involves the study of the basic nutrients required to sustain life, their bio-availability in foods and overall diet, and the effects upon them of cooking and storage. It is also concerned with dietary deficiency diseases. There are six classes of nutrients: water, carbohydrates, proteins, fats, vitamins, and minerals. Water is involved in nearly every body process. Animals and humans will succumb to water deprivation sooner than to starvation. Carbohydrates are composed of carbon, hydrogen and oxygen. The major groups are starches, sugars, and cellulose and related material (or ' roughage'). The prime function of the carbohydrates is to provide energy for the body; they also serve as efficient sources of glucose, which the body requires for brain functioning, utilisation of foods, maintenance of body temperature. Roughage includes the stiff structural materials of vegetables, fruits, and cereal products. Proteins are made up of smaller units, amino acids. The primary function of dietary protein is to provide the amino acids
required for growth and maintenance of body tissues. Both vegetable and animal foods are protein sources. Fats serve as concentrated sources of energy, and protect vital organs such as the kidneys and skeleton. Saturated fats derive primarily from animal sources; unsaturated fats from vegetable sources such as nuts and seeds. Vitamins are essential for normal growth, and are either fat-soluble or water-soluble. Fat-soluble vitamins include A, essential to the maintenance of mucous membranes, particularly the conjunctiva of the eyes; D, important to the absorption of calcium; E, an antioxidant; and K, which aids blood clotting. Water-soluble vitamins are the B complex, essential to metabolic reactions, and C, for maintaining connective tissue and cell functioning. Minerals are vital to normal development; calcium and iron are particularly important as they are required in relatively large amounts. Minerals required by the body in trace amounts include chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, and zinc. Research Nutrition
Henri Etienne Sainte-Claire Deville was a French chemist. He was born in 1818 and died in 1881. His principal works included the sodium method of preparing aluminium and researches on the platinum metals. His experiences with high temperature methods in this connection led to pioneering work on the artificial preparation of minerals and to his discovery of thermal dissociation. Research Henri Sainte-Claire Deville
Johann Rudolf Glauber was a German chemist. He was born in 1603 at Karlstadt and died in 1668. He was a zealous alchemist but his experiments resulted in valuable chemical discoveries. He was the first to produce hydrochloric acid from oil of vitriol and salt. He also discovered sodium sulphate, which is named after him as Glauber's Salt. Research Johann Glauber
Acidosis is a condition in which the body fluids tend to have a higher acid content than normal. The body has a variety of ways to compensate for mild acidosis, but prolonged acidosis can produce weakness, headache, and heavy or rapid breathing. Severe acidosis may lead to acidemia (a build-up of acids in the blood) which can result in coma and death. Acidosis itself is not a disease, but it may warn of the presence of a disease. It arises from disorders that cause the body to accumulate excess acid or to lose too much alkali. Most of these disorders are respiratory failures or metabolic failures. Respiratory acidosis results from such disturbances as severe lung disease, blockage of the upper air passages, and chest injury. Metabolic failures involve malfunctioning of the process by which the body changes food into energy and tissue. Metabolic acidosis arises from kidney failure, diabetes, poisoning, and severe diarrhoea. Treatment usually consists of correcting the underlying problem and administering sodium bicarbonate or another alkaline substance through a vein. Research Acidosis
The transfer of blood from one individual to another first became a practical proposition during the Great War. The recognition of four major blood groups indicated that there were limitations on blood transfusion which necessitated very careful examination of the blood of the two individuals concerned. In the early days of transfusion after preliminary grouping, the blood was transferred from the donor to the recipient by the ' direct' method, using a two-way tap and syringe, so that the blood was not exposed to the air and had no opportunity for clotting. The 'indirect' method was later introduced in which the donor's blood was received into a solution of sodium citrate which prevented it from clotting by inactivating the calcium. Within an hour or so the blood was then injected into the veins of the recipient. Prior to the second World War, most large hospital centres in Great Britain maintained a panel of blood donors who were willing to come to the hospital at any hour of the day or night for emergency transfusion. The relatives of patients also were called upon, if with the right blood group, to give their blood.
The necessities of war, and the greater demands of surgery for blood transfusion led to the establishment of ' blood banks', in which are stored large quantities of blood taken at a convenient time from thousands of volunteers. With suitable refrigeration, blood may be stored for three weeks with safety and such blood is quite suitable for the treatment of shock and conditions of blood loss. Certain other disorders, mainly medical conditions affecting the formation of red cells in the bonemarrow, are preferably treated with the transfusion of fresh blood: this seems to possess properties which become lost in storage. Blood transfusion performs a double purpose. It replaces the oxygen-carrying red cells and its fluidfraction, the plasma, contributes protein which maintains the circulating blood volume, thus preventing the escape of water into the tissues. Plasma or serum may be separated from the whole blood and dried. In this form it was used extensively during the Second World War because it could be stored indefinitely and could be reconstituted by the addition of distilled water when infusion was needed in the treatment of shock. By the extraction of the fluid portion of the whole blood, the cell content may be concentrated. Such a preparation is known as packed cells. This has become of particular value if it is necessary to raise the haemoglobin rapidly without raising the blood volume unduly. Such a procedure may be required in the treatment of severe anaemia arising from toxaemia. Research Blood Transfusion
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Aldebaran
