Category Scientist & Invensions

Hermann Ludwig Helmholtz, a German physician and physicist, is best known for the law of the conservation of energy. He also made significant contributions to physiology, optics electrodynamics, mathematics, and meteorology.

         In 1847, he published his paper ‘On the Conservation of Force’. This was the first explanation of the fundamental concept of conservation of energy. His inventions of the ophthalmoscope allowed physicians to see inside the eye, and revolutionized the field of ophthalmology.

       Helmholtz was a keen mathematician, and in 1858 published the paper which provided a key to the fundamental structure of matter. He also investigated the physics of tone and colour perception. But above all, it is his theory of the conservation of energy that is his greatest contribution, for it is one of the broadest and most important generalizations ever known in the history of science.

Claude Bernard, a French physiologist, has been called one of the greatest of all men of science. Bernard was fascinated with the mechanics of digestion.

        He made a number of experiments in which he made opening into the stomachs of live animals in order to study their workings. His experiments resulted in a number of important discoveries, including the finding that the small intestine played a key role in the digestive process.

      His experimentation also helped show the significance of the pancreas. In 1857, Bernard discovered glycogen, the large molecule found in animals’ livers which acts as a reserve store of carbohydrates, and helps to regulate blood sugar. Bernard also studied the nervous system. While engaged in this research, Bernard made the important discovery that oxygen was carried around the body by red corpuscles in an animal’s blood.

     Bernard was one of the founders of experimental medicine, and played a vital role in laying down the basic rules of experimentation in the life sciences.

Charles Darwin was an English naturalist who is best known for his ideas on evolution. In 1831, Darwin set sail on the HMS Beagle, a naval survey ship. Darwin’s job was to collect plant and animal specimens from the countries the ship visited. The voyage took five years.

      For Charles Darwin, the most important part of the journey was the time spent in the Galapagos Islands which are the home to plants and animals that can’t be found anywhere else in the world.

      On his return to England, Darwin stated to piece together his theory of natural selection which explains how populations evolve. In 1859, Charles Darwin published his book ‘On the Origin of Species’.

     According to this theory, all species of life have evolved over time from common ancestors. Charles Darwin changed the way humans viewed themselves.

Jean Louis Agassiz, a Swiss-American naturalist, was an outstanding comparative anatomist. When he was only 21 years old, he published the work that launched him on his long and distinguished scientific career. It was titled ‘The Fishes of Brazil’ and it was the most important account of a local fish fauna published till that time.

       Later, Agassiz worked under Georges Cuvier, another brilliant comparative anatomist. Agassiz made extensive contributions to ichthyological classification, including of extinct species.

      Ichthyology is the branch of biology devoted to the study of fish. Agassiz also played an important role in the study of geological history including the founding of glaciology. He was a person with many interests- a biologist, physician, geologist, teacher, and most importantly, a prominent innovator in the field of the study of natural sciences.

John Dalton, a British scientist, is probably best known for his groundbreaking research and contributions to two completely different fields- atomic theory and colorblindness.

It was discovered in 1995 that Dalton actually had a very rare form of color blindness- he was only able to see one colour, yellow.

So, he studied the problem in great detail and concluded that colorblindness was a genetic feature, as his brother was also colour blind.

Dalton was also very influential in the study of meteorology, specifically barometric pressure. This led to his publication of a series of papers called experimental essays in which he discussed the makeup of mixed gases.

The most important of all Dalton’s investigations are those concerned with the atomic theory in chemistry. The research had a great impact on atomic theory. He created a listing of atomic weights for six different elements – hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorous.

Dalton’s interpretation of atomic theory maintained that atoms are combined in chemical reactions, but also that they can be separated and rearranged. Without doubt, it was John Dalton’s atomic theory that laid the foundations of modern chemistry.

Friedrich Wohler was a German chemist who chose to be a teacher of chemistry. He was one of the finest scientists of the 19th century.

        Wohler gained international renown from two path breaking discoveries. In 1827, Wohler prepared the first pure sample of aluminum. This metal is the third most prevalent element in the earth’s crust, but it is exceedingly difficult to isolate it from its compounds.

        He also discovered how to make urea in the laboratory without the use of a living kidney. This was an important discovery, because it heralded the end of an existing theory that organic compounds could only be made by living things. Wohler was the co-discoverer of beryllium, silicon, and silicon nitride.

       In 1832, Wohler, along with another scientist Justus Liebig published a study on the oil of bitter almonds which proved that a group of atoms can act like a single element, and be exchanged for elements in chemical compounds. This too, took the scientific world by storm.