Carl Wilhelm Scheele 1742 - 1786 Apprentice apothecary. Carl Scheele was born December 9, 1742, one of eleven children.  He received very little formal education and no training whatsoever in science.  At age 14, Scheele became an apprentice apothecary of the firm Martin Anders Bauch in Gothenburg.  The supply of chemicals present in the pharmacy afforded Scheele with a starting point for many investigations and discoveries.  He also made use of the numerous scientific books of the day.  In 1765 Bauch sold the business and Scheele took a position with Kjellström in Malmö where he was again allowed to experiment.  In 1768, Scheele moved to Stockholm and again worked in a pharmacy.  Here he and Anders Johan Retzius isolated tartaric acid from cream of tartar.  The results were published in 1770.

Fire Air.  In 1770, Scheele moved to Uppsala where he became the assistant in the laboratory of Lokk.  It is here that Scheele discovered 'fire air' [oxygen] sometime before 1773.  He produced fire air several ways.  In the first method, he reacted (using modern names) nitric acid with potash (KOH and/or K2CO3) which formed KNO3).  Distilling the residue with sulfuric acid produced both NO2 and O2.  The former was absorbed by Ca(OH)2(sat'd), leaving oxygen (fire air).  He also obtained fire air from strongly heating HgO and MnO2 and by heating silver carbonate or mercuric carbonate and then absorbing the CO2 by alkali (KOH):

Recognition in Sweden.  On February 4, 1775, Carl Scheele was elected to membership into the Royal Academy of Sciences.  This great honor (with the King of Sweden was in attendance) had never before (and never since) been given to a student of pharmacy.

Köping.  In 1775, Carl Scheele moved to Köping, Sweden where he took a position as superintendent of the pharmacy.  By now Scheele was receiving various offers for improved positions from around Sweden.  The town of Köping did not want to lose their new famed son so they obtained for him his own pharmacy, previously owned by an apothecary named Pohls who had died.  Pohls's widow remained in Köping to manage Scheele's household.  It is believed that Scheele did not travel from Köping, but rather spent his time engaged in his scientific pursuits.

Communication problems.  In eighteenth Century Europe, the art of communicating one's results was primitive by today's standards.  Often scientists used personal letters describing results to contemporaries interested in the same work.  Scheele was isolated from much scientific literature although he did communicate with Lavoisier who sent him a copy of his early book.  Writing a book was the best way to disseminate results, however, it often took years to accumulate enough results for a book and then it could take years longer for the book to be published.  Such was the tragedy of Carl Scheele who discovered oxygen (fire air) two years before Priestley.  Scheele's book, Chemical Treatise on Air and Fire, was not published until 1777, by which time European scientists were aware of Priestley's discovery of the same gas (dephlogisticated air) in 1774.  At the time of his death, very little was known of Scheele's life, the poverty in which he lived, the cold in which he worked, his struggle with illness and his early death.  Over a century passed before two individuals, working with Scheele's notes, papers and letters held by the Swedish Royal Academy of Sciences, brought to the public in 1892 the important scientific contributions of Carl Scheele.²

Cyanide and marriage vows.  At Köping, Scheele prepared compounds of cyanide, including gaseous hydrogen cyanide, and even described its taste!  He also studied a variety of arsenic compounds.  Without proper ventilation, Scheele was frequently exposed to deadly poisons.  It is thought that this exposure seriously damaged Scheele's health and significantly shortened his life.  Scheele was aware of the cause of his poor health and he referred to it as "the trouble of all apothecaries."  Carl Scheele died at age 43 on May 26, 1786.  Two days before he died, he married the widow Pohls so that she would inherit the pharmacy and his belongings.
 

Lasting accomplishments.

•  Few, if any chemists have discovered more new simple substances than Scheele.  He is credited with:

• the discovery of oxygen, chlorine (which he called dephlogisticated marine acid), hydrogen fluoride, silicon fluoride, hydrogen sulfide, hydrogen cyanide.

• isolating and characterizing for the first time glycerol, tartaric acid, citric acid, lactic acid, uric acid, benzoic acid, gallic acid, oxalic acid, lactose, Prussic acid, arsenic acid, molybdic acid, tungstic acid, copper arsenite (called "Scheele's green")

•  First to report the action of light on silver salts (which became the basis of modern photography)

1 letter to his friend Johann Gahn, December 26, 1774 Famous Chemists, Sir William Tildon, London, 1921.

2 Nordenskjöld, Scheele, Nachgelassene Briefe, Stockholm, 1892.