Sunday, September 13, 2020

Western History 124: What were some of the key advances in Biology and Chemistry during the 17th and 18th centuries?

English physician William Harvey continued the tradition of Andreas Vesalius – the 16th century father of modern anatomy – by analyzing and describing the working of the body’s circulatory system in 1628.   

The empirical movement had galvanized physiology and this was given further impetus by the gradual improvement of the compound microscope that was first built in the late 16th century and improved by various parties in the early 17th century.  In 1665 the Englishman Robert Hooke identified the cell and  ten years later the Dutchman Antonie van Leeuwenhoek observed the first microorganism.

96. ANTONIE van LEEUWENHOEK – SAPAVIVA

Antonie van Leeuwenhoek source: sapaviva.com

There were other positive progressions as well. Francesco Redi dealt a serious blow against the Doctrine of Spontaneous Generation in 1669 while Jan Swammerdam (in 1668) was able to describe epigenesis in insects (the development of the adult insect from  an egg via cell differentiation). At around the same time Nicholas Steno established the science of stratigraphy by making the case that fossils were the remnants of organic material embedded in sentiment.

Carl Linnaeus | New Scientist

Carl Linnaeus source: newscientist

A significant development in biology occurred in 1735 when the Swede Carl Linnaeus devised a system for Taxonomic classification. This would serve as a  foundation for efforts to catalogue the web of life in the future.  Following on from his work Georges Cuvier (1796) would then advance the notion of extinction as a fact of life. This as well as the Principles of Uniformitarianism, Deep Time (Old earth) and Plutonic Geology set forth by the Scot James Hutton in 1785, would later underpin Charles Darwin’s thinking around evolution by natural selection.

In 1796 the Science of Immunology was born when another English doctor Edward Jenner demonstrated the efficacy of the cowpox vaccine as a tool against smallpox. Also of note in the annals of 18th century medicine was the first use of digitalis (taken from the foxglove plant) by William Withering in the treatment of Edema. It is used today to treat  heart rhythm problem.

Smallpox vaccine and a dose of truth | Vaccines and immunisation | The  Guardian

Edward Jenner source: theguardian.com

Advances in Chemistry were also expedited during the Age of Reason and the later Enlightenment.  In 1615 Jean Beguin became a pioneer in using chemical equations and the science continued to move ahead with the work of Jan Baptist van Helmont who wrote a foundational text in 1648 and established the field of pneumatic chemistry.

In 1766 the Englishman Henry Cavendish discovered Hydrogen and six years later oxygen was  likely identified by Swedish chemist Carl Wilhem Scheele although most give credit to Joseph Priestley (he published before Scheele). Priestley did make the case that the air we breathe consists of a variety of gases. Oxygen in Priestley’s view was a highly reactive gas that he called ‘dephologisticated air’.

Joseph Priestley | Science History Institute

Joseph Priestly source: sciencehistory.org

He was also responsible for developing the method to carbonate liquids that has influenced both the sodas and champagne industries of today. Carbon dioxide used in carbonation was discovered much earlier by Joseph Black in 1754 who described it as ‘fixed air’

The Father of Chemistry though is Frenchman Antoine Lavoisier who linked oxygen as the key gas involved in combustion. This ended the Phlogiston Theory that made the case that a fire-like element known as  Phlogiston was responsible for combustion,. Antoine Lavoisier is credited with developing a central tenet of chemistry – The Law of Conservation of Mass.

Antoine Lavoisier | New Scientist

 Antoine Lavoisier source:newscientist

18th century chemistry though was very much concerned with chemical identification and in this regard a debt of gratitude goes to Scheele who identified molybdenum. tungsten, chlorine, barium  and manganese.The Scot Daniel Rutherford  is worth mentioning as he isolated nitrogen in 1772.

However other avenues were growing in parallel. In 1800 Italian Alessandro Volta discovered the electrochemical series and went one step further by building the first chemical battery.

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