History of Chemistry and the Education of Teachers

Early in my teaching career I became convinced that history has value in causing the student to look at chemistry in a realistic fashion. But, like classroom demonstrations, history should fulfill a teaching objective and not be used merely as entertainment. Further, history is made by human beings and lends a human interest which is lacking when only the facts of chemistry are expounded (1). Merely telling students that Priestley discovered oxygen is a historical fact which frequently leads to some yawns and even the query, "Do we have to know that on the exam?" If we introduce Priestley at all, let's make him meaningful. Why did Priestley, a minister, carry out an experiment which produced oxygen? Because he wished to better understand the design of the Creator. Are you aware that many of the names in 17th and 18th century science were theologians and nearly all scientists of the day were deeply devout? That point is worth further discussion. Why was Priestley carrying out an experiment which produced oxygen? Because he was, like many of his contemporaries, a pneumatic chemist, Why were there so many pneumatic chemists at that moment? Because Stephen Hales, another theologian, had invented the pneumatic trough a half century earlier (2). For the first time in human history it was possible to isolate airs by decomposition of chemical substances and collect the resulting air comparatively free of contaminants. Hales developed the apparatus because he was curious to learn how much air was trapped in various solids in non-aerial form. He measured the volume of air which could be driven out of various chemicals, rocks, seeds, and plants by heating (3). Hales' objective was wrong. Rather than asking "How much air?" he should have been asking, "What kind of air?" At