Augustin Pyramus de Candolle – Swiss botanist

Augustin Pyramus de Candolle, (born February 4, 1778, Geneva—died September 9, 1841, Geneva), Swiss botanist was one of the pre-eminent botanists of the nineteenth century. He is best remembered for his contributions to plant systematics; however, he is the first scientist to provide a comprehensive account of allelopathy.

At the age of seven, he was stricken with hydrocephalus, but survived seemingly with no ill effects. He became fluent in Latin while at school, and seemed destined for a literary career. His taste for botany was stimulated by attending the lectures of Prof. J. Vaucher (1763–1841), a founder of the Geneva Natural History Society.

In 1796 de Candolle visited Paris for the first time, and at the young age of 18, he met several of the leading French scientists in natural history including Georges Cuvier, Desfontaines and Jean-Baptiste de Lamarck.

He became an assistant to Cuvier at the Collège de France (1802), and prepared revisions of Lamarck’s Flore française (1805, 1815).

He also had begun giving botany lectures at the College de France in 1804. In the same year he completed his dissertation for his degree in medicine, and this was published successfully as Essai sur les Propriétés Médicales des Plantes.

When he was appointed professor of botany at the University of Montpellier (1808), Candolle had already begun a government-commissioned botanical and agricultural survey of France (1806–12), the results of which he published in 1813.

Augustin Pyramus de Candolle – Swiss botanist

Euler, Leonhard (1707-83)

Leonhard Euler, one of the most prolific mathematicians in history is considered one of the founders of pure mathematics and analysis.

Euler was born on April 15, 1707, in Basel Switzerland. His father, Paul Euler, a Calvinist minister, and his mother, Margaret Brucker, married the year before his birth.  His interest and talent for mathematics showed itself early, and he received special instruction from Johann Bernoulli.

In 1720 Euler entered the University of Basel at the age of 14; there he discussed mathematics with Daniel Bernoulli.

In 1720 he joined the Department of Arts of the University of Basel, where he received the prima laurea in 1722 and in 1723 he earned a master’s degree in philosophy. He joined the Department of Theology, but devoted most of his time to mathematics.

In 1731 Euler moved to the department of physics as a professor. In 1733 Euler succeeded Daniel Bernoulli as first chair of mathematics at St. Petersburg. Frederick the Great invited Euler to become a member of the Berlin Academy in 1741 and he held joint appointments in Berlin and in St. Petersburg until he was appointed the director of the St. Petersburg Academy of Science in 1766.

His book Mechanica (1736-1737) provided the most mathematically sophisticated treatment of Newtonian and post-Newtonian mechanics to date, putting mechanics in analytic rather than geometric terms.

He also set forth, in New Theory of Light and Color (1746), a theory of light as vibration, as opposed to the dominant Newtonian the theory of light as a particle.

Euler wrote several papers on the physical constitution of celestial bodies (mainly on comets) as well as on celestial and terrestrial phenomena related to the Earth’s atmosphere or its magnetic field.

Euler’s devotion to his work lasted until the day he died, September 18, 18783, in St. Petersburg, Russia, where he spent time formulating laws of ascent for the recently invented hot-air balloon.
Euler, Leonhard (1707-83)