Short biography of Gerhard Henrik Armauer Hansen (1841-1912)

He was well known for his pioneer study of leprosy - a prominent disease in the history of human sufferings.

Armauer Hansen was the discoverer of the causative agent of leprosy. Armauer Hansen was born in 29 July 1841 in Bergen, Norway. He entered the University of Christiana to study medicine in 1859. He obtained his degree in medicine in 1866, and completed his internship at the National Hospital in Christiania. After about two years at Bergen’s Leprosy Hospital he underwent a period of study in Vienna, where he became familiar with the ‘germ theory’ of disease.

 

Returning to Bergen, Hansen was by now convinced that leprosy was a specific communicable disease. In 1873, he discovered rod-shaped bodies later identified as M. leprae. He published his observations in 1874. By improving his staining technique in 1879, he was able to show great numbers of rod-shaped bacteria typically aggregated in parallel.

In 1880 Hansen named the organism causing leprosy as Bacillus leprae. When Lehman and Neumann erected the new genus Mycobacterium in 1896, it was transferred to this genus and henceforth ahs be known as Mycobacterium leprae.

He believed that the bacillus was the etiological agent of leprosy, which proved to be true. Hansen’s publication from 1874, Preliminary Contributions to the Characteristics of Leprosy, is the earliest description of a microorganism as the cause of a chronic disease.
Short biography of Gerhard Henrik Armauer Hansen (1841-1912)

Gregor Johann Mendel

Gregor Johann Mendel Gregor
Johann Mendel was born in Heinzendorf, a village near the border between northern Moravia and Silesia, in Austrian Empire on July 22, 1822. He was an Augustinian priest and scientist, and is often called the father of genetics for his study of the inheritance of traits in pea plants. In 1851 he was sent to the University of Vienna to study, returning to his abbey in 1853 as a teacher, principally of physics.

Mendel began his experiments with the hybrid cultivation of pea plants in 1856. After spending eight years carrying out experimental work in the monastery garden, he reported on the results of his observations at the meetings of the Association for Natural Research in Brno on the evenings of February 8th and March 8th, 1865. His experiments brought forth two generalizations which later became known as Mendel's Laws of Inheritance.

Mendel's attraction to research was based on his love of nature. He was not only interested in plants, but also in meteorology and theories of evolution. Mendel often wondered how plants obtained atypical characteristics. On one of his frequent walks around the monastery, he found an atypical variety of an ornamental plant. He took it and planted it next to the typical variety. He grew their progeny side by side to see if there would be any approximation of the traits passed on to the next generation. He found that the plants' respective offspring retained the essential traits of the parents, and therefore were not influenced by the environment. This simple test gave birth to the idea of heredity.
Gregor Johann Mendel