Part 1: Traces on the Trail

Part 1 of 6 of an interview with David Peck, D.O.


Today we are at Travelers' Rest, which was the Lewis and Clark Expedition's campground, of early September 1805 and early July of 1806. My name is David Peck. I am a practicing physician in San Diego, and I am the author of Or Perish in the Attempt: Wilderness Medicine in the Lewis and Clark Expedition.

This is a great site, not only for its historic value as a campsite, but it's very interesting that they have recently established that there is a high level of mercury in the ground here, in an area where they believe that the latrine for the corps was located. This is an interesting aspect of the medical practice of Lewis and Clark, and the medical practice at that time in America. The reason for the high incidence of mercury in the ground was that one of the very popular medications that the Corps of Discovery was using at that time, and being administered by "doctors" Lewis and Clark, were the Bilious Pills(1) of Dr. Rush. Dr. Rush’s pills included a mercury compound called calomel, which is mercurous chloride. It is a mercury salt.(2) It was administered in combination with powdered jalap,(3) which is a Mexican morning glory root. These were very, very powerful cathartics, or laxatives, and these were used to treat all types of different illnesses.

Now, this form of mercury, the mercurous chloride, is very poorly absorbed from the intestine. Probably only 15 percent of the amount that is taken orally would have been actually absorbed into the body, the rest would pass through the intestinal tract and out. In fact that is one of the main reasons this was administered, because of its potent irritation to the intestine and producing a laxative effect. So consequently, when these men would take these Bilious Pills of Dr. Rush, for a variety of reasons, ultimately most of it would pass out in their bowel movements and then it produces this high quantity of mercury that is still found in this latrine area of Travelers' Rest.

The Lewis and Clark Expedition . . . in the medical bag that they took along on the expedition . . . interestingly enough, took along fifty dozen of Dr. Rush's Bilious Pills. I think that is evidence that they used them for a variety of different illnesses. Captain Clark even took five, which is a potentially fatal dose, near the three forks, for what Dr. Ron Loge of Dillon, Montana believes was the first case of Colorado tick fever.

Supported in part by a grant from the National Park Service, Challenge Cost-Share Program