Today, we find science where we thought we saw superstition. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Why did the old remedies hang on so long? Why did we keep bleeding sick patients? Ancient Egyptians used the so-called Balm of Gilead -- a poultice of butter and honey. We kept right on using it until modern times. Can you imagine smearing such a mess on an open wound!

Yet the same people invented trigonometry. The creators of the Italian Renaissance were still using those cures. We might wonder if inventive minds simply switched off when it came to medicine.

Maybe not! Take bleeding: Recently, a Canadian physiologist bled feverish animals. Sure enough, the fever went down. Of course he wasn't allowed to try it on feverish human subjects.

But see what history tells us: Roman doctors were clear about bleeding. It cut fever, but that's all it did. We finally had fever thermometers after the Civil War and before malpractice law. It was then that a German doctor measured the effect of bleeding on humans. Sure enough, it did reduce fever.

So, it seems, we owe our forebears more respect. Our technologies didn't get where they are by being silly or superstitious. Medicine has always been part foolishness. But then, as now, medicine included a whole lot of acquired truth, as well.

We credit Edward Jenner with inventing inoculation. Yet inoculation was also an ancient folk practice. Jenner himself made the connection after he talked to a milkmaid. She pointed out that you can't get smallpox if you've had cowpox first.

And what about that sugary Balm of Gilead? It too has come under new scrutiny. Sugar, it seems, is a very effective antibiotic. It's not clear why. Maybe it creates an osmotic pressure that kills germs by driving water out of cells.

We can go on and on like this. In 1856 the explorer Richard Burton wrote that Africans thought mosquitoes caused malaria. That superstition came about, he said, because malaria happened to arrive during the mosquito season.

Somehow, we still call that folklore -- not science. As far as we're concerned, the relation between mosquitoes and malaria wasn't discovered until Walter Reed figured it out.

It's easy to forget that any science is a system of beliefs -- not a body of truth. Ancient medical lore reminds us that a system of knowledge is only a garment we put on. Ancient medicine reminds us that strange people, in strange garments, can know far more than we like to admit.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

Root-Bernstein, R.S., Ends & Means. The Sciences, March/April, 1991, pp. 10-12.