Background

Each of us has a world view that influences or even determines how we act and react. New ideas challenge us. Competing ideas lead to changes in what people think and how they behave, whether through reason or force. In 1864, Abraham Lincoln presided over a country divided by a bloody civil war that defined certain principles of human dignity for which the United States continues to aspire. There were other less violent changes occurring in 1864. Louis Pasteur, who had recently introduced the idea of optical isomerism with tartaric acids, worked to convince critics that fermentation of glucose to ethanol and carbon dioxide occurred within living cells and soon he would refute ideas of spontaneous generation (1). Charles Darwin's, The Origin of Species published in 1859, continued to challenge scientists and the public to confront their relationship to other living things and their religious convictions (2). In an Austrian monastery, Gregor Mendel worked on the genetics of peas not knowing the profound effect his ideas would have on biology in the next century. Many things that we take for granted were unknown or viewed differently in the mid 19th century. As you read this 1864 article by G. G. Stokes, try to understand what he did and how you would describe and interpret his work in terms of your own scientific world view.

Sir George Gabriel Stokes (1819-1903) became Lucasian Professor of Mathematics at the University of Cambridge in 1849. This prestigious professorship once was held by Sir Isaac Newton and now is held by Stephen Hawking (3). Like Newton, Stokes served both as president of the Royal Society (1885) and as a conservative member of Parliament (1887-1892) (4). His studies of viscous fluids led to the deduction of a mathematical formula now known as Stokes' Law, the context in which most science students encounter Stokes. One wonders how Stokes, a renown mathematician and physicist (5,6), ventured briefly here into the world of chemistry and biology.

As he states in the article's first few sentences, an article by Hoppe, a German physiological chemist, on the absorption spectrum of a dilute solution of blood (7) attracted his attention and he became curious about how chemical reagents might affect the colored compound's beautiful spectrum. Light and its interaction with matter was a major interest of Stokes (8). Among other things he thought a great deal about the propagation of light in a vacuum (7). As a leading expert on light in the 19th century, Stokes was well prepared to exploit the spectroscope introduced by Kirchoff and Bunsen in 1860 (9).

We begin this course with Stokes' article because it represents one of the early attempts to understand the function of blood in chemical terms. We will spend about six class periods discussing this one article. It and subsequent articles will be difficult to understand at first. Be patient and persistent. Through the semester you should discover the learning power that comes from an ability to recognize and pursue areas of personal ignorance. Research scientists pursue their personal ignorance to the limits of human knowledge and there they work at the boundary between knowledge and ignorance. A scientific paper should address questions of the unknown and expand the realm of the known. What did Stokes report that was new? What do you know that Stokes did not know? What do you need to learn that is known that will help you understand Stokes' article?