Every newcomer to the Lewis & Clark Journals makes the delightful discovery that the explorers wrote so strongly in their own voices that it is almost possible to hear Meriwether Lewis’s Virginia drawl and William Clark’s bluegrass twang resonate off the pages. Creative spelling has a lot to do with the charm of the journals. Back then, spelling had not yet been standardized, and both explorers tend to sound out the words the way they would have pronounced them.
Clark in particular raised spelling to the level of performance art, and never was he more creative than when writing of one of the Expedition’s greatest pests, known to us as the “mosquito.” Clark came up with no fewer than 19 variations, including mesquestors, misquestors, misquitor, misquitoes, misquitors, misqutors, misqutr, missquetors, mosquiters, mosquitors, mosquitos, muskeetor, musqueters, musquetors, musquiters, musquitoes, musquitors, musqueters, and musqutors.
It’s fun to have a chuckle at Clark’s expense, but no matter how you slice it (or spell it), the frequent journal entry “mosquitoes very troublesome” was no laughing matter. The wandering Missouri River created many swamps and backwaters which bred billions of mosquitoes on the Great Plains. At times the insects attacked the Corps of Discovery so ferociously that it was impossible for them to shoot their rifles accurately for all the bugs swarming in their faces. They were frequently driven to move campsites to try to escape the mosquitos, with their only defense being smoky fires, mosquito netting, and a smelly repellant they made from tallow and hogs’ lard. There were many nights that they couldn’t even eat without taking in mouthfuls of bugs.
Our trio of pests still invade and obstruct us on all occasions, these are the Musquetoes eye knats and prickley pears, equal to any three curses that ever poor Egypt laiboured under, except the Mahometant yoke. – Meriwether Lewis, July 24, 1805
As if being under siege by biting insects wasn’t bad enough, mosquitoes posed another danger, one Lewis and Clark didn’t understand. It would be eighty years before pioneering scientists realized that that mosquitoes were a disease vector, almost one hundred years before they conclusively proved the matter. Until then, malaria, along mosquito-borne yellow fever, would be the bane of the American frontier. In fact, malaria may well have been a significant contributor to the death of Meriwether Lewis just three years after the Expedition.
Malaria (also known as “the ague” — pronounced ay-gyuh) was known to originate in the swamps, but the medical thinking of the day held that the dank, fetid air somehow caused the disease. In any case, ague was as common as a cold in frontier America, so universal that it was considered hardly worth mentioning. Moreover, like the cold, it could be contracted again and again; some forms of the disease can also produce recurring symptoms months or even years later. Thomas Jefferson, James Madison, and probably William Clark were among the chronic sufferers; it is likely that every member of the Corps suffered from painful, debilitating ague at one point or another.
Upon the onset of a case of malaria, the sufferer experiences fever, joint pain, vomiting, red urine, and severe chills. Eventually, the fever can spike to 105 degrees, bringing on a knee-buckling headache. Finally, an extreme sweating breaks the fever. Most victims recover, though some, especially children, suffer permanent damage to the eyes and brain.
The best treatment for the ague was one of the world’s first great miracle drugs. Jesuit missionaries in the 1600s had learned from the Indians of a substance called Peruvian bark (the bark of the cinchona tree) that could help alleviate the fever of malaria. When he equipped the Expedition’s medical kit, Lewis brought along 15 pounds of the pricy imported bark (later shown to contain the alkaloid quinine). Lewis was known to treat malarial symptoms in others with the bark, but for himself, he turned most often to what he considered a quick fix: Rush’s pills, a powerful patent medicine laxative containing high doses of mercury.
Chronic malaria may have played a role in Lewis’s death in 1809. As Thomas Danisi details in his biography of Lewis’s post-expedition life, frontier military physicians record patients so tormented by headaches, eye pain, and severe inflammation of the spleen and liver that they had to be restrained from suicide. In addition, it is entirely possible that Lewis was suffering mercury poisoning from his use of Rush’s pills; headaches, ringing in the ears, and nausea from the use of Peruvian bark; and/or the effects of the laudanum and wine that was used to make the medicine more palatable. Danisi writes that Lewis may have committed suicide in a last, desperate attempt to end his suffering.
While the drainage of wetlands led to the end of malaria in the United States, the disease continues to be a worldwide scourge, especially in Africa, where hundreds of millions of human beings are infected and two to three million people die from malaria every year.











I did not write anywhere in the book, “Danisi writes that Lewis may have committed suicide in a last, desperate attempt to end his suffering.”
I wrote that Lewis tried to alleviate his pain. In sum this is what I am trying to say: Historians, in the past, have claimed that Lewis killed himself; I am claiming that Lewis did not mean to kill himself in his malarial attack – rather he meant only to treat his absolute pain.
Thanks for the clarification on your position, Thomas. Your book has an excellent discussion of malaria and its possible effects on Lewis.
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