OUR SCIENTISTS: 02/10/09

Tuesday, February 10, 2009

CARL WILLIAM SCHEELE

CARL WILLIAM SCHEELE
( 1742 - 1786)

Swedish scientist, self-educated. He used to work as an assistant in pharmacies and showed a talent in chemistry from a very young age. In spite an offer made to him to study in London or Berlin, he operated a pharmacy in kipping where he spend the rest of his life and made all his important inventions. He was especially interest on chemical analysis and worked particularly with the chemical reactions between silver nitrate and sunlight, therefore making a break through in the chemistry of photography. The records from his experiments were of a great importance for the next generations of scientists.

UGLICHNO MARCONI

UGLICHNO MARCONI

( 1874 - 1937)

Marconi is the inventor of wireless telegraphy and radio. He was born at Bologna in Italy on 25 April 1874. He was encouraged by his mother to do research. Marconi was conducting experiments in his father’s estate after he studied physics in a technical school. He showed interest in sending telegraphic messages without the help of wire. He had come to understand that Heirich Hertz had believed that radio waves could be used to carry messages. Marconi sent wireless messages. He positioned an electric bell in between many instruments in one corner of the room. He went to the other corner of the room and pressed the Morse Key. (Samuel Morse. The inventor of telegraphy). To his surprise the electric bell placed at a distance of 30 feet rang. The ringing of the bell with the radio waves was possible. In an another instance, he placed his self made transmitter on one side of a hill and received the message on the other side. This experiment made him to send messages to long distance also. By 1897 he had succeeded in rado communication over a distance 20 kilometres. He established the Marconi company in 1897. In 1899, He transmitted a radio signal across the English channel a distance of nearly 50 kilometres.

Marconi’s invention made radio broadcasting to begin in England on 14th February 1922. Radio is the term applied to methods of signaling through space, without connecting wires, by means of electromagnetic waves generated by high frequency alternating current.

Marconi was made the president of the Royal Italian Academy in 1930. Several changes took place in radio communication after its invention by Marconi. He lived to see all of them. He died on 20 July, 1937 in Rome. In 1909 Marconi received the Nobel Prize for his invention.

HOMI JEHANGHIR BHABHA

HOMI JEHANGHIR BHABHA

(1909 - 1966 )

Famous Indian scientist who was instrumental in establishing the Atomic Energy commission in India. Bhabha was born on October 30, 1909 into a wealthy Parsi family. Even as a child he showed interest in science. His father wanted bhabha to become an engineer and sent him abroad for higher studies. But bhabha’s interest like Enrico Fermi and the Austrian Physicist Wolfgang Pauli.

Bhabha made research on cosmic rays. He joined the Indian Institute of Science, Bangalore. Cosmic rays are fast moving, extremely small particles coming from outer space. They were detected first by V.F.Fless in 1912. Cosmic rays are atomic nuclei accelerated to very high energies. They are highly penetrating. When these rays enter the earth’s atmosphere they collide with the atoms in the air and produce showers of electrons. Along with W.Heitler, a German physicist Bhabha solved the mystery surrounding these rays. Bhabha recognized the presence of a new nuclear particle in the showers which he called ‘meson’. In 1940 he retuned to India from England as second world war broke. He was elected fellow of the royal society for his contributions relating to cosmic rays and quantum mechanics.

Due to the concerted efforts of Bhabha Tata institute of fundamental research was set up. He set up this institute with the encouragement of the then. Prime Minister of India Jawaharlal Nehru a prestigious centre for research in nuclear physics which later came to be known as the Bhabha Atomic research centre. Bhabha’s interest was to make India, a nuclear powered country. Under his guidance three atomic reactors Apsara, Cirus and Zerlina were built. He was also responsible for the construction of the country’s first atomic poer station at Tarapur. The station began in 1963. Two years later a plutonium plant was installed. He also encouraged research electronics, space science, radio astronomy and microbiology. The radio telescope at Ooty is one of his creations. He was of the attitude tha atom is for peace. He was one of the eminent members of the ‘atom for peace’ conference. It is on 24 January 1966 Bhabha died in an aircrash on his way to attend an international conference. He was 57.

Bhabha was a person of varied interests. He spend his spare time painting and writing poetry. He was fond of western classical music. He was a first class painter. His pencil sketches are famous. Few paintings of Bhabha are still preserved in British art galleries.

Homi Bhabha was a bachelor. He was once asked if he was married. ‘Yes’ he replied and then siling he added, ‘to creativity.’

HIPPOCRATES

HIPPOCRATES (B.C.)

Today the doctors who came out of the universities take an oath that they serve mankind. The oath they take is in the name of Hippocrates, the father of Medicine. The oath runs as follows:
“Into whatever houses I enter, I enter to help the sick; If anyone shows interest in learning this process of treatment for implementation I shall offer guidance free of cost. My education is law abiding.”

Hippocrates was born on the Greek Island of COS. He was the son of a priest. In those days the Greeks believed that the people suffered from diseases because of the displeasure of Gods and the sick people had to go to the temple and accept ointment and medicines from the priests only. Hippocrates when he was brought up did not believe in this mode of healing of the patients. He believed only in the facts ascertained by experiments and observations in treating patients suffering from diseases. He said:”diseases are not God sent to be taken back by Gods”. He also said that every disease had its own explanatory cause and if this element of physical cause of the disease is detected they may be treated to cure it. Nothing is achieved by sleeping in temples and offering prayers.

According to Hippocrates nature is the best healer. In the treatment of disease nature plays an important role. In the maintenance of good health he advocated these facts namely (1) Creation of healthy or sick free atmosphere (2) Development of personal or individual habits.

Hippocrates depended upon hydro therapy. He used a mixture of hot and cold waters for the treatment of fever, wounds etc., He demonstrated as to how cold water bath would give comfort to man, retaining the body temperature also. He preferred Sub bath for TB patients. He said to them to drink fresh and good milk.

Hippocrates became successful because of his scientific approach. Experimentation, observation and inference. He detected the causes and the symptoms of the disease he cured. He told doctors to examine the patients carefully and note down the symptoms of the diseases and begin the treatment.

Hippocrates’s Aphorisms are popular.

WILLIAM GILBERT

WILLIAM GILBERT
( 1540-1603 )

English physician; known for his early studies on electricity and magnetism. His De magnete (1600) propounded the theory that the earth was a giant lodestone with north and south magnetic poles. His theory that the earth exerted a magnetic influence throughout the solar system was a precursor to the modern conception of gravity as an attracting force between masses. Gilbert was among the first to divide substances into electrics (spar, glass, amber) and nonelectrics.
Centuries later, the English physicist William Gilbert (1540-1603) was able to show that it was not amber alone that acted so, but that a number of other substances as well gained an attracting power when rubbed. About 1600, he suggested that substances of this sort be called "electrics", from the Greek word for amber.
As a result, a substance that gains such a power, through rubbing or otherwise, is said to carry an electric charge, or to contain electricity.

HEINRICH RUDOLPH HERTZ

HEINRICH RUDOLPH HERTZ

( 1857 - 1894)

Hertz was a German Scientist. He opened the way for the development of radio. Television and RADAR with his discovery of electromagnetic waves.

Hertz was born on 22 February 1857 at Hamberg into a rich family. He studied architecture and mechanical engeneering. But he developed interest in science and research. He worked under Herman Won Helm Holt in Berlin university. He got his degree in 1880. He went to Keel as a teacher where he studied electro magnetism. Manwell had opined that electric and magnetic waves can be transmitted as light waves. Hertz desired to prove this statement. He made transmitters to transmit electro magnetic waves and receivers to receive them. This has helped today’s Radio, TV and Radar.

Hertz used a rapidly oscillating electric spark to produce waves of ultra high frequency. He showed that these waves caused similar electrical oscillations in a distant wire loop. He also showed that light waves and electromagnetic waves were identical thus proving James C.Maxwell’s theoretical conclusions.

Hertz determined the wave length. He confirmed that the speed of electro magnetic waves is equal to the speed of the light waves. It is 300 million metres.

Hertz is the SI unit of frequency of a periodic phenomenon. It is the number of repetitions of a periodic phenomenon per second. It is named after the scientist Heinrich Hertz. The symbol is Hz. Eg: the frequency of aleternating current used in India is 50 Hz.

HARAGOBIND KHURANA

HARAGOBIND KHURANA

(B.1922)

Haragobind Khurana, the Indian Scientist is the third Indian who won Nobel Prize in the field of physiology and medicine in 1968. He shared it with Robert W.Holley and Marshall W.Nirenberg for interpretation of the genetic code and its function in protein synthesis.

Khurana was born on Jan 2, 1922 at Rajpur in Punjab. He was the son of a village tax collector. The family was illiterate in the entire village. But khurana studied well and passed degree examination from Lahore college. He took post graduate degree in chemistry in 1945 from Punjab university. Then he went to Manchester University for higher studies. He obtained his doctorate degree in 1948. On his return to India, he was disappointed. He could not get a job for many months. He went back to England and worked with Nobel Laureate Sir Alexander Todd at Cambridge University. In 1952 he went to Canada and married the daughter of M.P.Switzerland.

Khurana helped to decipher the Genetic Code by recreating Synthetically each of the 64 possible triplets of DNA (De onyribo nucleic acid) which work in combination as instructions for the protein synthesizing mechanism of the cell. He succeeded in Synthesizing the first wholly artificial gene. It was E.coli or Escherichia coli.

E.Coli is a bacteria that lives in the intestines of human beings and animals. Khorana and his team worked to build a gene of this organism. Piece by Piece they built up the 207 genes of this bacteria. In August 1976, the man made gene was inserted into E.Coli which began to work like the natural gene. Khorana’s achievements made available a technique to change genes and observe the results of those changes.

Khorana is the recipient of many awards. To mention a few he has been given Merch award of the chemical institute of Canada, Gold medal of the professional institute of Canadian public service, Dannie Heineman prize, Lasker foundation award and Louis Horutiz prize.

Khorana has published more than 300 papers on genetic research. He is Padma Bhushan.

HALDANE J.B.S.

HALDANE J.B.S.

(1892 - 1964 )

Haldane was an English born Indian biologist. He was born on November 5, 1892 at oxford. Even as a child he was different from other children. When he was a two year old he was immitating the faces of various dogs. He was experimenting upon himself. His father was a noted physiologist. He helped his father in experiments. He learnt many languages and read books on various subjects. He was sharp in mathematics which brought him Russell prize at 16. He was taught at Cambridge and at university college in London. He did reaserch in Biochemistry. In 1925 he showed interest in genetics and elected the fellow of Royal Society in 1932. He was made professor of Genetics in University college, London.

He decided to emigrate to India in 1957 and got citizenship in 1961. He didn’t go back to England. He made contributions to several diverse subjects such as medicine, evolution, physiology, genetics, biochemistry, mathematics and cosmology. He estimated the rate of mutation of a human gene. He said that mutation, the sudden change in a gene occurs once for every 50,000 people per generation. He wrote two books titled ‘Enzymes’ (1930) and ‘The causes of Evolution’ (1932). They are scientific classics. His discoveries in biochemistry have been known as laws of enzyme chemistry.

He did research in physiology also. He found how chemicals, CO2 gas, ice cold temperature affect breath. He discovered cure for tetanus and convulsions. His book ‘My friend Mr.Losakey’ is specially written for children.

While in India, he was inspired by Hindu philosophy and the principle of nonviolence. He liked to wear dhoti and kurta. He was appointed a professor at the Indian statistical institute, Kolkata. He was director, Genetics and Biometry laboratory, Bhuvaneshwar. He died of cancer at Bhuvaneshwar at the age of 71. Even at his death bed he was cheerful and wrote a poem ‘Cancer’s a Funny Thing’. He had made research on colour blindness and haemophilia.

John burdon Sanderson Haldane, Popularised science during his life time. He was also a social worker.

VON LIEBIG

VON LIEBIG
(1803-1873)

German chemist, Justus von Liebig (1803-1873) who, by 1831, could obtain fairly reliable empirical formulas as a result. (Liebig was one of the great chemistry teachers of all time. He taught at the University of Giessen, where he established the first real laboratory course in chemistry. Numerous chemists studied with him and learned laboratory procedures from him. Liebig was one of the influences making chemistry, in which France had been pre-eminent in the eighteenth century, almost a German monopoly in the nineteenth century.) Soon afterward, in 1833, the French chemist Jean Baptiste Andre Dumas (1800-1884) devised a modification of the method, one which allowed the chemist to collect nitrogen also among the products of combustion. In this way one could determine the proportions of nitrogen in an organic substance.

IVAN PETROVICH PAVLOV

IVAN PETROVICH PAVLOV

( 1849 - 1936)

Pavlov was a Russian physiologist who won the 1904 Nobel prize in physiology or medicine for unraveling the mechanism of the digestive process and his work provided psychology with a more objective methodology and led to new methods of treating mental illness. Using dogs for experiments he established the idea of conditioned reflexes which for example, makes a pre conditioned dog salivate merely on hearing a bell, in expectation of food though it may not be actually there.

Pavlov demonstrated his theory of conditioned reflex in 1901. In 1920 he extended his theory of animal behaviour to human psychology. He invented new techniques in his work. He provided a foundation for modern gas troenterology and behaviourist school of psychology.

HIPPOLYTE BAYARD

HIPPOLYTE BAYARD
( 1807 - 1887)

The most unfortunate from the pioneers of photography. Discovered one direct positive photographic method. He was the first person to hold a photographic exhibition (for humanitarian reasons) and the first who combined two negatives to created one print (called Combination Printing). As a civil servant and with five hundred franks that received as financial help from Arago for improving his method, prevented him from presenting the discovery of photography at the French Academy of Sciences.

GAY LUSSAC

GAY LUSSAC

( 1778 - 1850 )

Joseph Louis Gay Lussac was a French chemist and physicist. He stated Gas laws.

Gay Lussac was a physics lecturer at Sorbonne and he became a professor at the Ecole Polytechnique. In 1802 he reformulated Charles Law of thermal expansion of gases.

Charle’s law states that the volume of a given mass of gas at constant pressure is directly proportional to the absolute thermodynamic temperature; equivalently all gases have the same coefficient of expansion at constant pressure.

Gay Lussac’s Law states that when gases react they do so in volume which bear a somple ratio to one another and to the volume of the resulting substances in the gaseous state, all volumes being measured at the same temperature and pressure. That is the gases combine chemically in simple proportions by volume.

Gay Lussac also obtained sodium and potassium in 1808 and 1815. He was the first to obtain an acid without oxygen or anhydrous prussic acid. He developed new methods of volumetric analysis.

Jean Baptiste Biot was Gay Lussac’s friend. Both were physicists. They once made a daring balloon flight which took them to more than 7000 metres. At an elevation of about 7016 metres the balloon stopped going high and Gay Lussac threw all kinds of things off from the ballon. It is said that the people who were peasants who saw them believed that the objects were throuwn from heaven.

Gay Lussac proposed the law of combining volumes in 1809 which states that gases form compoiunds with each other in simple, definite proportions which can be expressed by the formula of the compounds.

Eg: Formula for water – H2O shows that it is formed of 2 parts of hydrogen and one of Oxygen.

Gay Lussac also improved processes for making sulphurc and oxalic acid in industry.

GREGOR JOHANN MENDEL

GREGOR JOHANN MENDEL

(1822 - 1884)

Mendal was the father of modern genetics. He was an Austrian monk. He studied science at Vienna University. He taught natural sciences at the monastery school at Brunn (Bruno in Czech). It was a technical high school.

Mendal was fond of nature. He loved flora and fauna. He cross bred different varieties of Pea Plants and studied different characteristics like colour, height and seed shape. He observed that each characteristic was passed on to the next generation independently of the other characteristics and various characteristics in the parent plants recombined randomly in their off springs. He conducted breeding experiments for about nine years to explain the mechanism of inheritance. This led him to formulate his laws. According to him the individual characteristics are determined by inherited factors which are governed by two laws namely the Law of Seggregation and the Law of Independent Assortment.

Law of Seggregation says that each hereditary characteristic is controlled by two factors which separate and pass into separate reproductive cells. Their individualities are maintained.

Law of independent assortment states that pairs of factors separate independently of each other when reproductive cells are formed.

The factors regarded for the expression of special nature have been identified as genes. The genes are transferred from the parents to their children during reproduction. There may be few exceptions. That is they differ in some respect or the other which is called variation. Both the genetics and variation are the basis for the evolution of the species.

Mendel presented his work at the meeting of Brunn Natural Science Society in 1865. But this was not much attended at that time. However his work was rediscovered in 1901. Mendel spent his last few years of his life experimenting with bees. He had the Apiary surrounding the monastery. He died in the year 1884.

WILLIAM HENRY FOX TALBOT

WILLIAM HENRY
FOX TALBOT
( 1800 - 1877)

Professor of literature, egyptologist, mathematician, classicist, physicist, transcriber of chaldean cuneiform texts, who with his inventions on photography created the foundations for the development of this art and science for the next one hundred and fifty years. After a trip to Italy, where he used camera lucida for complicated designs, decided to discover a more practical and easy way to record images. He succeeded quite early, in 1835 by creating the first negative. His greatest discovery the negative process, minimizes exposure time considerably compared to passed methods. With the help and guidance of his friend Herschel achieves extraordinary results, which announces on January 1839 at the Royal Society and since then English and French argue on who first announced the discovery of photography.

SIR FREDRICK GRANT BANTING

SIR FREDRICK GRANT BANTING

( 1891 - 1941 )

Banting was the Canadian physician. He was a medicinal scientist. He extracted the insulin hormone from the Pancreas. Insulin is a protein hormone which is produced by the islets of Langerhans of the Pancreas. It is widely used in the treatment of diabetes mellitus. Banting’s research made it possible to prolong the lives of the victims of diabetes. Otherwise they were facing death as the level of glucose accumulation in the blood stream was to be higher. Banting isolated insulin in a fantastic way. His assistant was Best. Both tied the Pancreatic duets of several dogs for a period of seven weeks, after which the Pancreas crumbled up and were functionless as digestive organs. The is bets of Langerhans remained intact and a solution was extracted from these cells. Banting and Best did their work in the laboratory of John J.R. Macleod at the university of Toronto. Macleod didn’t participate in the work. But still Nobel Prize in physiology and medicine was awarded to both in 1923. They shared where as Best didn’t get anything. But Banting sent half of the award amount to his assistant charles H. Best. They demonstrated the role of insulin in controlling the blood sugar levels. Insulin injection results promptly in decline in blood glucose concentration and an increase in formation of products derived from glucose.

Banting died in 1941.

FREDRICK WOHLER

FREDRICK WOHLER

(1800 - 1882)

German chemist Fredrick Wohler was the first to synthesize an organic compound ureas, from an inorganic chemical. The synthesis destroyed the belief that organic substances could only be formed in living plants or animals.

Wohler was born in July 1800 in a tiny village near Frank Fortommaine. His father guided him well. Wholer showed keen interst in chemistry. He did many experiments using voltaic cells. He joined Marberg university to study medicine at 20. he examined the impure objects produced in the human body to turn out as urine. He got his medical degree from Hidelberg University. But he did research in chemistry as per the suggestion made by his chemistry professor. He went to Stockholm and worked under chemist Bezelius. He made a compound silver cyanate using nitrogen, carbon, oxygen and silver. Wohler found another scientist Justace Livebig who made the same compound whose formula remained same. But these two same compounds had different properties and behaving differently. These two scientists became close friends.

Wohler made potassium cyanate and when it was mixed with ammonium sulphate needle shaped urea or ammonium cyanate crystals were produced. This was a new discovery. Till such time no such organic chemical was made. It was a mile stone in the development of science.

Wohler also developed a process for preparing metallic aluminium, and isolated beryllium and yttrium. He died in 1882.

HERCULES FLORENCE

HERCULES

FLORENCE

( 1804 - 1879)

Few details are known for his life. In 1824 goes to Brazil and takes part in a scientific mission at the Amazon, whre he becomes preoccupied with the idea of recording images from his trip. From 1830 devotes himself to research and experimentation for photography. The above gives Brazil the ability to claim that is one of the places in the world, where photography was found.

EUCLID

EUCLID

(300 B.C.)

Euclid is called the father of geometry. He was the Greek Mathematician and wrote the book ‘Elements’ the oldest mathematical work. The first printed version of Elements appeared in 1482 in Latin and the first English translation was published in 1570. It was used as a reference book until 20th century and regarded as a model of logical reasoning. It is understood that Euclid was educated in plato’s academy. He is supposed to have been taught in Alexandria.

‘Elements’ is a set of thirteen valumes which contain information about point, lines, circles, triangles, ratio and proportions, solid geometry and geometrical figures like sphere, pyramid etc., Euclidian geometry have become famous all over the world.

Euclid said, “There is no royal road to learning. In geometry all must go the same away.”

Once Euclid was teaching geometry to students. A student stood up and asked him. “Can you tell me just what is the practical advantage in studying geometry?”

Euclid didn’t answer him. He called his servant and said, “Give this gentleman some money. He cannot learn without money.”

Once few teacher asked Euclid to tell how to measure the height of a great pyramid as there is no way. But Euclid smiled. He measured the length of the Pyramid’s shadow at the precise time when the length of his shadow was exactly equal to his height.

Euclid said that is it impossible to become a theoretical researcher if one does not practice geometry. The other books written by Euclid are data, division of figures, phenomenon, surface, lociprisms, and cones common lessons in music.

In the middle of 19th century new methods different from that of Euclid were introduced and new books were published. They are called non Eucledian methods. David Hilbert was the pioneer of this new method in 1899. Albert Einstein took help from Euclidian geometry to develop his theory of relativity. He said that two events in his youth were important of which one is the study of Euclidian geometry at the age of 12.

ERNEST LORD RUTHERFORD

ERNEST LORD RUTHERFORD

( 1871 - 1937)

Rutherford gave us the description of an atom. He showed that there is a small part inside an atom. He developed atomic theory resembling description of a solar system. He raid that an atom is composed of a heavy nucleus in the center, with a positive charge of electricity and negatively charged electrons surrounding it.

Rutherfor was born on August 30, 1871 in Newzealand. He was educated in Newzealand and pursued his higher studies at Trinity college, Cambridge University.

He worked under physicist J.J.Thomson. In 1898 he became the professor of physic at Mc.Gill university in Canada and studied radioactivew disintegration. In Cavendish laboratory he deiscovered that there were different kinds of rays given off by radioactive substances. He called them alpha and beta rays.

He distinguished them and showed that radio activity involved natural transmutation of rado active elements. The alpha rays helped him to decide the structure of an atom. For his work on radio active substances he was awarded the Nobel prize for chemistry in 1908. in 1917 he successfully bombarded nitrogen with alpha particles, changing the atoms to oxygen atoms and he became the first person to change one metal into another. He was appointed Director of the Cavendish laboratory in 1919. Rutherford named hydrogen nucleur ‘Proton’. He was the President of the Royal Society from 1925 to 1930.

He died on 19 October 1937 at Cambridge in England. He was buried in West Minister Abbey. The element Rutherfordium whose atomic number is 104 is named after him in his memory. Rutherford’s conclusion that an atom consist of a small positively charged nuclears became the basis for Wiel’s Bohr’s work on the atomic structure. Wiel’s Bohr and Rutherford were intimate friends.

ENRICO FERMI

ENRICO FERMI

( 1901 - 1954)

Fermi, the Italian – American Physicist was one of the pioneers of the nuclear age. He was born on 26, September 1901 in Rome. At the age of 21, he obtained his Ph.D. in the fields of X-rays from the university of Pisa. In 1926 he made his first major contribution to physics with his work on the statistical behavious of a monoatomic gas, later called Fermi gas. In 1927 he was appointed as a lecturer of physics in Rome University. Ten years of research he discovered that when a element is bombarded by a slow moving neutron, it becomes adioactive and starts emitting radiations. The result is, one element charges into another element. In 1933 he discovered a neutral particle called neutrino. He produced eightly new artificial nuclei by neutron bombardment.

Fermi went to USA on an invitation to speak at Columbia University. Thereafter he remained there only. In 1938 he was awarded Nobel Prize in Physics. He became a professor in the Columbia University in 1939 and a US citizen in 1944. he designed the first nuclear reactor in Chicago. The reactor generated the energy by nuclear fission. He was instrumental in developing of an atombomb during the second world war.

Fermi joined Chicago University after second world war. The institute of nuclear studies there was name after him. In 1944 – 45 he had served as Associate Director of the Los Alamos Laboraory in New Mexico. He received the medal of merit in 1946. He was the recipient of the first annual award of the Atomic energy commission in 1954. 100th element fermium was named after him. An award called Fermi award was instituted in his honour and is awarded for outstanding work in Science in America.

Fermi died on 28 Nov, 1954 in Chicago.

EDWARD JENNER

EDWARD JENNER

(1749 – 1823)

Today we have number of life saving Vaccines for several diseases. These vaccines are produced on Jenner’s theory. Edward Jenner was a British Physician who established the practice of vaccination. He is the discoverer of small pox Vacination. Small pox is fully eradicated. This was a dreadful disease 250 years ago. Usually people suffering from it died. Those who survived would have become ugly or blind. Jenner found vaccination for prevention of small pox.

Jenner was born on May 17, 1749 at Berkely. He studied medical science, while he under went training under a surgeon, he observed in 1766 milk maids once ‘infected with cow pox developed a life long immunity to small pox. Cow pox is a disease of cows. One who milks a cow suffering from this disease can get it. After completing his training Jenner began his medical practice in 1773. he ascertained that cow pox protects from small pox only when cow pox is introduced at a particular stage. In may 1796, he inoculated an 8 year old boy with fulid from cowpox listers. Two months later, he inoculated the boy with live active small pox virus but the disease did not follow. Nobody took Jenner’s experiment seriously. Few practioners believed that cowpox and small pox were two different diseases some people made adverse remarks stating that injecting a fluid from a cow into the human blood is a dreadful act. But Jenner ignored them. Actually, Jenner’s was the first successful immunizing procedure against any disease. Jenner won world wide admiration for his discovery. He was awarded by British parliament. He also made further discoveries about animals. But he devoted his whole life on fighting against small pox.

Jenner died in 1823 at Berkely, until 1881, the cow pox vaccine was the only inoculating material available. To day innumerable vaccines have been developed and they are being made effective. The principle of vaccine has been extended to prevent fertility.

AMEDEO AVOGARO

AMEDEO
AVOGADRO
(1776 - 1856 )
Amedeo Avogadro was an Italian scientist born in the Kingdom of Sardinia ad Piedmont, most noted for his contributions to the theory of molarity and molecular weight. He was born on August 9, 1776. The number of molecules in one mole is called Avogadro’s number is honor of him, as is Avogadro’s law.

Avogadro’s law implies that the relationship occurring between the weights of same volumes of different gases (at the same temperature and pressure) corresponds to the relationship between respective molecular weights. Hence, relative molecular masses can be calculated from the masses of gas samples.

Avogadro developed this hypothesis after Joseph Louis Gay-Lussac had published in 1808 his law on volumes (and combining gases). The greatest difficulty Avogadro had to resolve was the huge confusion at theat time regarding atoms and molecules ? one of most important contributions of Avogadro’s work was clearly distinguishing one from the other, admitting that simple particules too could be composed of molecules, and that these are composed of atoms.

In 1820 he became a professor of Turin’s university. With suspicious enthusiasm, he took part in political revolutionary movements of 1821 (against the king of Sardinia), so two years later he was removed from his position (or as it was officially declared, the university was very glad to allow this interesting scientist to take a rest from heavy teaching duties, in order to be able to give a better attention to his researches). Well before this, following the increasing attention to lus works, Avogadro had been recalled at Turin university in 1833, where he taught for another twenty years.

In honor of Avogadro’s contributions to the theory of molarity and molecular weights, the numbr of molecules in one mole was renamed Avogadro’s number.

But his own time, Avogadro’s principle was seriously neglected. Historians of science have several theories as to why this should be so, as Avogadro was a respected scientist during his life. But the real reason is probably more prosaic. In the clannish world of scientific discovery, it pays to be at the center of the action. Avogadro was by this time a professor, and chairman, of physical chemistry at the University of Turin. But in Italy far away from the major science centers of England, Germany, France or even Sweden. He never got to rub shoulders with the “great ones” of his day, so his ideas did not receive the credit they deserved.

He was a professor until his retirement at the age of 74. He died on July 9th, 1856.

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