To Know About Pioneers of Atomic Age

Antoine Henri Becquerel (1852-1908) was a French Physicist who discovered radioactivity.

Some substances, when they have been exposed to bright sunlight, glow in the dark for some time afterwards. This effect is called Phosphorescence. Henri Becquerel followed in the footsteps of his father and grandfather who had both been well-known physicists. He was interested in crystals which glow (fluoresce) after absorbing sunlight. When Roentgen discovered X-rays in 1895, Becquerel was fascinated. In the meanwhile a Frenchman named Henri poincare, who later became famous as a brilliant mathematician, suggested that phosphorescent substances might give off X-rays. In 1896, a friend and fellow-countryman of Poincare, Antoine Henri Becquerel, decided to put the matter to the test. He exposed crystals of a Uranium compound to sunlight to make them phosphorescent and placed them on thickly wrapped photographic plates. On developing the plates he found that the plates had been blackened by rays from the uranium compounds. It looked as if Poincare had been correct. A few days later Becquerel happened to be developing some old photographic plates to see if they were still good enough to use. The plates had been kept in a drawer in which there were traces of the uranium compounds. He found to his astonishment that those plates had been blackened by the uranium, even though they had been kept in the dark. The blackening had nothing to do with phosphorescence after all. Becquerel had discovered what came to be called radioactivity. He found that the uranium ore pitchblende was more intensely radioactive that even uranium itself. His enthusiasm influenced Pierre and Marie Curie.

The Curies

Becquerel was friendly with Pierre Curie, a lecturer in Physics at the University of Sorbonne in Paris, and his wife Marie, who was a chemist. He mentioned his discovery regarding Pitchblende to them, and they resolved to try to isolate the unknown, powerfully radioactive element that must be present in the ore.

The Curies obtained loads of Pitchblende ‘waste’ from the Austrian government from which the uranium had already been extracted. They worked in an old wood shed in the Sorbonne purifying and separating the ore. In July 1898 they announced that there were not one, but two unknown radioactive elements in pitchblende. They isolated one, which Marie Curie named polonium, after Poland, where she was born. They did not succeed in isolating the second one, which they called radium, until 1902.

For their pioneering work on radioactivity, Becquerel and the Curies were jointly awarded the 1903 Nobel Physics Prize.

The radium the Curies had prepared so far was in the form of a compound. Therefore, they set about producing pure radium. Pierrie, however, was killed in a street accident in 1906, and Marie continued alone. Breaking with all tradition, the Sorbonne offered Pierre’s position to Madame Curie. In 1910 Marie succeeded at last in preparing a minute amount of pure radium. This brought her a second Nobel Prize in 1911. Soon afterwards she helped to found, and became the first director of the Radium institute of Paris.

Marie Curie died of leukemia, a disease of white blood cells. It has since been shown that radiation can cause leukemia, so it is more than likely that Madame Curie died as a result of excessive exposure to the intense radiation from the elements she had discovered. 

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How Leech Therapy is quite effective in treating patients

The word ‘unique’ denotes ‘one of its kind’ or something very special. Some animals are quite unique in this sense. For instance, the blue whale is unique for its giant size and so also glow worms “Luciferae” that emit greenish glow at night. Likewise, there are a few more creatures which are unique.

Leech the parasite doctor, is a very special physician. Dr Andreas Michalsen and colleagues from Essen, Germany reported that Leech therapy is quite effective in treating patients with osteoarthritis. Twenty-four patients with this wear and tear of the ageing knee problem were given one-shot leech therapy. They allowed four to six leeches to attach themselves to each knee and drink blood for about an hour. They found leech therapy was far more effective than drug therapy.

Leech therapy which benefits those with other causes of pain, was used by the ancient Egyptians, Greek and Indian medicine men. They used the leech to help maintain the humoral balance in the body. They attached leech to the body for the cure, and detached it by sprinkling some slat water.

How it acts as a physician: The leech which is used in medicine is called Hirudo

 Medicinalis. It has five pair of eyes and two sucker both on its front and back side.     .

The head sucker searches and penetrates while the back sucker holds fast to the host. The

Bite of hirudo is painless because it has an anaesthetic that makes the host feel nothing. This substance is under atudy.

The effect of its saliva:  The leech saliva has many other molecules of great medicinal interest. One of the molecules is a vaso-dilator and a histamine that increases the diameter of blood vessels, helping to promote blood flow. Another is an enzyme called hyaluronidase. It breaks down hyaluronic acid, the bonding material of the connective tissue, thus fostering the flow of blood and fluids from affected areas. Another substance in leech saliva is hirudin. It is the most potent inhibitor of blood clotting known to date. Hirudin in leech helps continued blood flow by breaking off the aggregated fibrin plugs that clot and seal blood leaks. Hirudin also shuts off the mechanisms of Factor VIII mediated blood coagulation. Genetic engineers in England are successful in cloning the gene for hirudin and manufacture it through recombinant DNA technology. We have to be thankful to the leech for the benefits it has opened up for modern medicine. Hirudin made it possible to have its cousins balellin and eglin.

How much blood it drinks: Leech drinks hardly 15ml our of the 3000-5000 ml of the human blood. And having drunk, the parasite doctor moves on to chew the cud for six months.

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Insects Of The World and how they work

Insects Of The World

Spiders are the most abundant arachnids, totaling about 30,000 species. They play an important role in the balance of nature by eating insects. Spiders have the ability to produce silk, a strong, elastic protein of many uses. They use it to make webs for trapping prey, to provide shelter, to protect the eggs, and for the tiny young to “balloon” along on wind currents on a delicate strand of web. The silk is produced as a liquid in abdominal glands, spun out of tiny spinnerets below the back end of the body, and hardens as it comes into the contact with the air.

The spiders have eight legs and eight simple eyes. Few spiders have poison dangerous to humans.

Black Widow is a dangerously poisonous spider that lives in warm parts of the world, but other widow spiders are found in colder climates. Female black widows are about half an inch long; the male is smaller. In most parts of the United States the red hourglass on the underside of its abdomen is the recognition mark of this species, but in other places marking vary from irregular strips to dots. The female black widow builds her irregular web in dark niches under objects near buildings or dumps.

Tarantula belongs to Theraphosidae family. These largest spiders are often called bird spiders in other places, and monkey spiders in South Africa. The tarantula of the Mediterranean area is not in this group, but belong to the wolf spider family. The largest, a South American species has a body 31/2 inches long and a 10-inch leg spa. Most of these spiders live on ground and a few in trees. The tarantulas are nocturnals. They hunt prey by sensing their vibrations. Though insects are their usual diet, occasionally large tarantulas captures a small snake, lizard, or nesting bird. Tarantulas, except for a few kind in Australia, are not dangerously poisonous to humans.

Sowbugs  are also called woodlice or pillbugs. They are sometimes mistaken for insects or millipedes. But they are crustaceans like lobsters, shrimp, and crayfish. Sowbugs differ from insects in having 14 instead of just six legs. Sowbugs are medium-sized, usually flattened animals with a shiny, hard covering over the back. The covering is divided into about 10 flexible plates, and some sowbugs, like armadillos, can roll up into a ball when disturbed. We find them usually under stones, boards, and other debris. They feed on decaying matter and fungi. They are usually harmless, but sometimes they damage the roots of cultivated plants.

Millipedes : None of the “thousand-leggers” – as millipedes are sometimes called – really has thousand legs. Most have fewer than 200. The newly hatched young ones may have six legs, and more are added each time they mould until they mature. There are two pairs of legs on most segments of the long, cylindrical body. Inspite of many legs, millipedes move slowly. Some species roll up when disturbed. These animals cannot bite or sting. Rarely, they become pests in localized areas by feeding on living plants. Millipedes live outdoors in damp, dark places such as leaf mould, and rotting logs, and they feed on decaying plant matter.

Centipedes, or Hundred-leggers are fast, active, nocturnal predators of insects and spiders. The house centipede is found in buildings in temperate climates and frequents damp places under sinks or tubs or around water pipes. It is harmless to humans and is probably beneficial in eating pest insects, but it startles people because of its unusually long legs. Tropical centipedes can inflict painful bites.

Springtails are tiny arthropods with a forked spring on the underside of the abdomen. It enables them to flip into the air when disturbed. They are often abundant on the surface of fresh water or sometimes on snow, when they are commonly called “snowfleas”. Others live on shores of oceans, lakes and ponds, but most are in moist humus or soil. They are common on the soil of house plants, where they are quite harmless, but they can become minor pests of agricultural crops by feeding on germinating seeds or living plants, and they sometimes infest mushroom cultures. Usually they eat moulds and decaying organic matter. Springtails are wingless.  

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