The Chemical History of the Candle

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Tues 9:30a ET/6:30a PT
Dr. Christe Ann McMenomy

Introduction to the study of Chemistry

An Introduction to the Study of Chemistry
Using Faraday's Lectures on the Chemical History of the Candle

Contents of this webpage

Read the Introduction and Preface

The introduction, by J. Arthur Thomson, gives you some background on Faraday's life.

  1. What does Thomson think makes scientific knowledge different from other kinds of knowledge?
  2. How did Faraday learn about chemistry?
  3. Why did Faraday repeat the experiments someone else had already done?
  4. Where did Faraday live for most of his working life?
  5. What challenges did Faraday face in gaining recognition for his discoveries?
  6. Thomson claims that the value of Faraday's work was in the theoretical discovery, rather than in the practical value. Why were his discoveries so important? What were some of the "practical" results of his work?

The preface, written by E. N. Da C. Andrade, tells you something about the Royal Institute and the history of the Christmas letters.

  1. When was the Royal Institute established? What other events were happening about the same time?
  2. Who was Humphrey Davy? How did his lectures on science influence Faraday?
  3. What were some of the things that made Faraday a successful lecturer?

The picture to the right is a portrait of Faraday giving a lecture in 1856. Notice the children in the first rows!

Michael Faraday's accomplishments

One of the many members of the general public who attended Sir Humphry Davy's popular lectures on electrical phenomena was a bookbinder named Michael Faraday. Faraday's formal education ended when he was 13, but his position in the book bindery gave him the opportunity to read about many subjects. He took notes at Davy's lectures, studied, and eventually applied to Davy for a job as an assistant. Davy hired at less money than Faraday made binding books, but took him on a grand tour of Europe, where Faraday met Ampère and Volta.

Inspired and encouraged by these contacts, Faraday continued to train himself. He was driven not only by his own curiosity but also by an abiding conviction in the unity of the created order, a conviction which grew out of his Christian faith. Despite frequent illness (probably from the same mercury poisoning which appears to have caused Davy and Newton problems), he managed to not only put in long hours at his laboratory, but also to give public lectures and to support his local church.

Today Faraday is universally acknowledged as one of the finest experimentalists in the history of science. His researches included studies of chemical compounds, electromagnetic phenomena, the behavior of gases, and the nature of light. He invented the first electric motor (in 1821), in which current flowing through a coil of wire caused a magnet to move. Having shown that electricity could cause magnets to move, he then spent the next decade trying to produce the reverse phenomenon, and generate electrical current in a coil by moving a magnet. Finally, in October of 1831, he was able to successfully produce electromagnetic induction; this invention is the electric generator or dynamo.

Faraday's two inventions, the electric motor and the electric generator, are fundamental necessities in our modern dependence on electrical power. Faraday was not interested in their commercial application, however; he left the development of his discoveries into practical applications to others. He was primarily interested in satisfying himself of the underlying principles of electricity, or chemistry. After publishing his successful attempt at electromagenetic induction, Faraday went on to determine how much electricity was necessary to separate elements during electrolysis, the process of passing current through solutions which Davy had used to isolate sodium, calcium, barium, and other substances from their compound forms. In the 1840s, Faraday showed that polarized light passing through a magnetic field would change its direction of polarization, but he lacked the mathematical theory to explain why this worked.

Faraday tried to develop a way of thinking about electricity and magnetism that would be more useful than the limited concepts of "electrical fluids", which could not explain how magnetic and electrical phenomena interacted. Since he was not a mathematician, he tended to think in pictures, and it is to Faraday that we owe the idea of force fields, which we now use to explain how all kinds of forces­electromagnetic, gravitational, and nuclear­work.

Discussion points

Web Resources

If you are interested in more details about Faraday, you might look at the following sites:

How to write a Lab Report

I'm going to use the generic "he" in these lectures, because the grammar is clearer. However, this does not in any way indicate that I think girls cannot be scientists!

First, determine what curious object you will observe: we will investigate how a candle burns.

Get a sense of the scope of your observations: we will experiment with several different areas of burning candle characteristics, not just focus on one area. Make a note of your goals in your lab notebook.

When you investigate a curious object, you start with close observation. Before you take any measurements, you must first try to identify what things are present, both as part of the object and part of its surroundings. Try not to think about what you should observe because you already know something about the situation, but look closely at what you do observe. Sometimes we are so conditioned by our expectations that we may easily miss important details that call our theories into question!

As you look at your curious object, make a mental list of the characteristics you could or should note and identify those that are subject to measurement or quantification. Check for shape and color, brightness and intensity of light, heat and temperature, size and mass (amount of matter) — and the boundaries where these change. Look for similarities or differences and patterns in composition, behavior, circumstances or environmental conditions surrounding the curious object. Make notes of these observations in your lab book.

Watch the curious object over time, and note not only what changes occur, but the rate of change. Look for characteristics most likely to affect the rate of change (amount of matter, temperature, outside forces acting on the object).

Now you are ready to make an hypothesis, an educated (by your observational experience) prediction of how the curious object will behave in a given set of circumstances. The best way to test this is to identify a single factor or circumstance that you can easily control and vary. Figure out what materials you will need. Make a list of the materials you actually use in your notebook!

Figure out what equipment you will need to take measurements and record data. Make a list of these in your lab notebook!

Set up several instances or trials of your observational situation, and vary your selected condition over a range of possible values, observe any changes in the behavior of the curious object and make your planned measurements. Be sure to have a control trial — one in which your variable factor isn't really a factor. This will help you identify whether other conditions may be affecting your outcome! Record your data in a useful format (perhaps a table organized by trial runs) in your lab notebook.

If your measurements require you to do so, make any necessary calculations. If you do your calculations using a spreadsheet or calculator, you should still include an example of your calculations in your lab notebook, and list your calculated data.

Now think about your data. Go back to your original observations and reflections and remind yourself what you were trying to discover about the curious object. Did your experiment cover the question you wanted to ask? Did it really test your hypothesis? What was the result (your hypothesis is true/false or needs refinement)? Put your thoughts and reflections in your notebook!

    You are ready to write your formal report. It should, of course, have a title, and each section should be clearly marked.
  1. Start by briefly describing the general observation that led you to investigate this particular phenomenon.
  2. State the hypothesis you wish to test, or the goal of your observation if you are not testing a true-false hypothesis (e.g., to determine what effect diameter has on the rate at which a candle burns).
  3. Identify your materials and equipment.
  4. Explain how you built any equipment or modified existing equipment for your experiment.
  5. Describe your procedure and your trial setup; be sure to include your control setup.
  6. List your data in a convenient format, one that allows the reader to see trends or discontinuities. Tables and graphs are good ways to show data.
  7. Show an example of your calculations (if any), and the final results of calculations for each of your trial runs.
  8. Summarize your conclusions. It's a good idea to also note what difficulties you ran into, any problems that might limit the applicability of your results to a general case, how these could be addressed in further experiments, and what the next steps in investigating your curious object should be.
  9. Write a short one-paragraph summary of your experiment and your conclusions as an abstract. This will actually go at the beginning of your report, but you can't really write it until the rest of the report exists.

There are a number of good sites on the web with details on lab report formats and how to write them. You may wish to consult

© 2011 This course is offered through Scholars Online, a non-profit organization supporting classical Christian education through Internet-based courses. Permission to copy course content (lessons and labs) for personal study is granted to students currently or formerly enrolled in the course through Scholars Online. Reproduction for any other purpose, without the express written consent of the author, is prohibited.