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Teaching Units & Lesson Plans

Using Primary Sources


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Lesson Plan 1: What Was the Medical Theory in the Early 1800s?


Students will:

  • describe the major medical beliefs practiced by Dr. Benjamin Rush, the medical adviser to the expedition
  • identify the Euro-American medical misconceptions of the nineteenth century
  • identify plant cures that have withstood the test of time



Benjamin Rush


Medical instruments

Medicine chest


Benjamin Rush's rules of health


Content Vocabulary Sheet (PDF)

Transcription of "Benjamin Rush's rules of health" (PDF)


Today medical cures are manufactured from chemical substances and come in the form of pills and injections. But before synthetic drugs and penicillin were discovered in the early twentieth century, most medicines came from plants. The concept of using plants for health and healing purposes has been around for more than five thousand years. Potions, elixirs, salves, and herbal preparations against illness and misery all trace their roots to the Egyptians, the Sumerians, the Mesopotamians, and other ancient cultures.

Members of the Lewis and Clark expedition could have encountered malaria, influenza, tick-borne fevers, yellow fever, frostbite, hypothermia, snake bites, giardiasis, cryptosporidiosis, tularemia, trichinosis, and a host of other health threats. Experts are amazed that the Corps of Discovery lost only one man (possibly due to appendicitis), given the limits of medicinal knowledge at the time and the physical demands of navigating on the upper Missouri River.

At the time of Lewis and Clark's expedition, physicians typically resorted to "treating" patients by methods such as purgation, sweating, salivation, blistering, and/or bleeding. Lewis learned about medicine from the country's most renowned doctor, Benjamin Rush. Rush believed that illness was caused by "morbid acrimonies" or "morbid excesses" that should be flushed from the system with laxatives, diuretics, emetics (for vomiting), agents that induce sweating, or by opening veins and draining pints of blood.

Before embarking on the expedition in 1804, Lewis purchased from an apothecary in Philadelphia dozens of medicines. His purchases included bilious pills (laxatives), diuretics, emetics, and a walnut medicine chest. For medical tools, he brought a clyster syringe (for enemas), surgical instruments, a tourniquet, and two lancets for bloodletting.

Many of the drugs in Lewis's medicine chest were believed to expel impurities from the body. We know that Lewis packed his medicines in glass-stoppered bottles and tin boxes, but there is no record of what his medicine chest looked like. His medicine chest contained a number of plant-based remedies such as quinine from a Peruvian tree bark to cure malaria; a purgative jalap from the Mexican morning glory; the emetic ipecacuanha from the Brazilian ipecac vine, and the painkiller opium from Turkish poppies. He also purchased herbs such as cinnemon, nutmeg, cloves, camphor, and peppermint (Mentha piperita). Lewis listed under medical supplies "1/4 lb. Es. Menth. Pip." (essence of Mentha piperita) which he purchased for $0.50, and two ounces of gum camphor purchased for $0.40.

Why did he pack nutmeg, clove, peppermint, and camphor? These herbs were thought to have medicinal purposes. Several medicinal uses for nutmeg are listed in twenty-first-century reference books; one source describes nutmeg as a cure for insomnia. It is possible that nutmeg, with its gentle bouquet, erased cares and worries from the insomnia sufferer. As for cloves, the oil of clove has been known to soothe toothaches. Peppermint possesses a number of uses; it was applied as an oil or "essence" when mixed with alcohol, was used topically as a cooling agent. When dissolved in warm water, peppermint was taken internally as a stomach sedative and was used to flavor other medicines. Hard gum of camphor could have been used as a topical salve for rashes and also as a mild irritant. When applied to a patient's chest, it produces relief for respiratory sweat.

While on the expedition, Lewis used other natural remedies that were new to him instead of relying solely on his limited medical chest. For example, on June 18, 1806, one of the men, John Potts, cut his leg badly with a knife. Lewis was able to stem the bleeding, but the wound became infected and painful. On June 22, 1806, Lewis applied some cous roots to the wound, which seemed to help. On June 27, 1806, the wound was better but hadn't healed. Lewis found some wild ginger growing in the forest of the Bitterroot Mountains. He wrote, "We applied the pounded roots and leaves of the wild ginger and from which he found great relief."


Display the painting of Dr. Benjamin Rush. Tell the students to imagine they are living in the 1800s. They are ill and need medical attention. Their parents seek out the best doctor of the time and call upon this man, Dr. Benjamin Rush, of Philadelphia. Dr. Rush, who trained Lewis before his expedition, wrote: "to know that opening a vein in the arm, or foot, would relieve a pain in the head or side...marks an advanced period in the history of medicine."

Explain to students that Dr. Rush's theory was highly regarded by Euro-Americans at the time. He treated patients by inducing purging or vomiting or by bloodletting, sometimes up to three pints of blood a day.

Show the image of the lancet. Lancets were used to bleed the patient. Mention that they were used by Lewis and Clark on their expedition. We now know that use of a lancet to cure could be worse than the illness itself. Lewis used it to treat dehydration, not knowing that his patients desperately needed their fluids. He resorted to his penknife when the lancets were not handy.


  1. Distribute (or project on an overhead) copies of Dr. Rush's rules of health. Use the document-analysis guide to direct student analysis of the document.

  2. After the reading, discuss the students' general impressions first. The following questions based on content can be used for discussion:

    • what were "raw spirits"?
    • what do we know now about the effect of raw spirits?
    • would raw spirits help fight fatigue?
    • what do we know now about the cause of constipation?
    • is constipation a sign of a disease?
    • what benefit would "shoes without heels" offer?
    • what do Dr. Rush's rules tell you about the misconceptions Euro-American doctors had at that time toward treating patients?
    • what misconceptions did Dr. Rush have toward treating patients?

  3. Teacher may want to read or paraphrase to students the information about the medical chest from teacher-background information under lesson 1.
  4. Show the image of the nineteenth-century medicine chest. Ask students what they think is in the bottles.
  5. Review content vocabulary list.
  6. Display the following quote from Clark, written while he wintered at Fort Mandan with the Mandan Indians:

    "a verry fine worm Day one man taken violently Bad with the Plurisie, Bleed & apply those remedies Common to that disorder."

    26th of January Satturday 1805

    [pleurisy was an inflammation of upper inner-chest area]

  7. After providing students with information about some of the contents in the chest [from background reading], ask the following questions and record students' responses on a board or paper for later reference when they work on their culminating performance assessment project.
    • what types of illnesses or injuries did Lewis anticipate?
    • what plants did Lewis take with him on his expedition?


Close with students imagining they were living in 1804. Would they want to be treated by Dr. Rush or by Lewis and Clark? Why?


To be assigned as homework: Write your own "Rules of Health" and what recommendations you would make to someone about to embark on a journey to a new territory. How would you change Dr. Rush's rules? What would you advise?


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