Marko T. Leko ( sr-cyr, Марко Т. Леко) was a notable Serbian scientist,

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe th ...

, professor and president of the Serbian Red Cross. He played a major role in the

professionalisation Professionalization is a social process by which any trade or occupation transforms itself into a true "profession of the highest integrity and competence." The definition of what constitutes a profession is often contested. Professionalization ten ...

chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

in Serbia. Leko was born in

Belgrade Belgrade ( , ;, ; Names of European cities in different languages: B, names in other languages) is the Capital city, capital and List of cities in Serbia, largest city in Serbia. It is located at the confluence of the Sava and Danube rivers a ...

Serbia Serbia (, ; Serbian language, Serbian: , , ), officially the Republic of Serbia (Serbian language, Serbian: , , ), is a landlocked country in Southeast Europe, Southeastern and Central Europe, situated at the crossroads of the Pannonian Bas ...

, on September 17, 1853 to a merchant family. He attended and graduated from Polytechnic School in Zurich and obtained his doctoral degree in 1875. For a short period, he was employed in Hoffman's laboratory.

Career

He has 52 publications mostly in the areas of organic and

analytical chemistry Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ...

. Thanks to work he dedicated in writing his doctoral dissertation and the number of works that followed, he was able to solve one of the most sought problems of the time: does ammonium chloride and its closely related compounds belong to compounds of five valences

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

, N H₄ Cl, or to compounds such as NH₃·HCl. His work in analytical chemistry had two main interests: researching natural resources of Earth (

mineral waters Mineral water is water from a mineral spring that contains various minerals, such as salts and sulfur compounds. Mineral water may usually be still or sparkling (carbonated/effervescent) according to the presence or absence of added gases. Tr ...

), and finding and improving new analytical methods. He was also interested in the chemical properties of natural spas and streams, and a stream located in Palanački Kiseljak bears his name ''Marko Leko''. In 1899 he was promoting spas in

Obrenovac Obrenovac ( sr-cyr, Обреновац, ) is a municipality of the city of Belgrade. According to the 2011 census results, the municipality has a population of 71,419 inhabitants, while the urban area has 24,568 inhabitants. The largest Serbian th ...

region. Leko was an active member of the Serbian

Red Cross The International Red Cross and Red Crescent Movement is a Humanitarianism, humanitarian movement with approximately 97 million Volunteering, volunteers, members and staff worldwide. It was founded to protect human life and health, to ensure re ...

. At first, he was a treasurer (1915–1920), vice president (1921) and president (1924).

Teaching

At the time of the founding of

Belgrade University The University of Belgrade ( sr, / ) is a public university in Serbia. It is the oldest and largest modern university in Serbia. Founded in 1808 as the Belgrade Higher School in revolutionary Serbia, by 1838 it merged with the Kragujevac-ba ...

in 1905, he was elected as an associate professor. He was deeply offended by this decision and on his own request retired early, on May 26 of 1905. In 1895, Sima Lozanić, a fellow chemist, drafted a secondary textbook for chemistry, which Leko was asked to review. Leko put forward 36 objections to the draft. Leko and Lozanić argued the points for 2 years through correspondence to ''The Educational Gazette'', at which point the Gazette refused to publish any more argument on the matter. One of the major issues was Lozanić's classification of N3 as an

allotropic Allotropy or allotropism () is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements. Allotropes are different structural modifications of an element: th ...

modification of

Nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

. His teaching posts included: * 1880-1884: Professor of Chemistry in Belgrade's secondary schools * 1881-1894: Professor of Chemistry at the Military Academy of Belgrade * 1894-1905: Professor of Chemistry at the University of Belgrade (then Belgrade Higher School) (part-time from 1894, made full Professor 1899) * 1884 became a member of Serbian Academic Society * 1892 became a member of Serbian Royal Academy * 1902/3 and 1903/4 was the Dean of then Great School * 1904-1920 state chemist and superintendent of State's Chemical Laboratory in Belgrade

Serbian Chemical Society

In 1897, Leko was the Manager of the Government Chemical Laboratory in

. The 3rd International Congress on Applied Chemistry was scheduled to be held in 1898, so the Main Committee for that Congress wrote to Leko suggesting a Serbian committee be organised to stimulate interest in the Serbian academic community. The first meeting of the Serbian Chemical Society was held on 15 November 1897 in Belgrade. The society did not create the office of President until 1904, at which time Leko was appointed as President of the Serbian Chemical Society. He was replaced in approximately 1907 at his own request, given he would be absent from the country while performing the role of President and Chief Manager of the Balkan Exhibition in London. During the period he was president, Dr Leko wrote 68 papers for the Society. Leko also authored a report on the Society's activities: 'A Contribution to the Development of Applied Chemistry in the Kingdom of Serbia' (1906).

Personal life

Leko had a large family. With his wife Danica (née Antula) he had eleven children. As parents they dedicated much of their time to their children education: five of his sons were noted jurist (Dušan M. Leko), chemist (Aleksandar M. Leko), architect (Dimitrije M. Leko), general (Jovan Leko), banker and financier (Dragoljub M. Leko). His brother

Dimitrije T. Leko Dimitrije "Mita" T. Leko ( sr-cyr, Димитрије Т. Леко; January 22, 1863 – September 24, 1914) was a Serbian architect and urbanist. Biography He spent most of his life outside Serbia and finished high school in Winterthur before s ...

was a renowned architect.

Death

He died on 4 November 1932 in Belgrade. Many important dignitaries of the time paid tribute to the scientist: the King Alexander I, members of the Royal government, members of the central committee of Red Cross and members of academia and Belgrade University. One of Belgrade's street, close to National Theater, bears his name. Before being renamed after him, the street bore the name ''Golden angel'' after the little family store owned by his father.

References