In the 1660s, Robert Hooke looked through a primitive microscope at a thinly cut piece of cork. He saw a series of walled boxes that reminded him of the tiny rooms, or cellula, occupied by monks. Medical historian Dr. Howard Markel discusses Hooke's coining of the word "cell."
(Soundbite of music)
Unidentified Man: The alphabet has only 26 letters. With these 26 magic symbols, however, millions of words are written every day.
IRA FLATOW, host:
That music means that it's time for this month's episode of Science Diction, the origin of science words. Our regular guest expert is Howard Markel, professor of history of medicine at the University of Michigan, Ann Arbor, and director of the Center for the History of Medicine there. Welcome to SCIENCE FRIDAY. Welcome back, Howard.
Dr. HOWARD MARKEL (History of Medicine, University of Michigan): Hey, Ira.
FLATOW: What word do we have today?
Prof. MARKEL: Well, the secret word is cell.
FLATOW: Here comes the duck.
(Soundbite of laughter)
Dr. MARKEL: Yeah. I was wondering what was out there. Yeah. You know, the basic building block of living life, and that's our word today.
FLATOW: And the origin?
Dr. MARKEL: Well, you know, given their size, it's not surprising that someone had to come up with a microscope first and look at them. And that task fell to the famed British natural philosopher Robert Hooke. And he was looking at it in the 17th century. He was actually looking at a thinly cut piece of cork. And while he was doing that, he noticed a series of walled pores that were not very deep but they consisted of boxes. And they reminded him of the rooms that monks stayed in. And those were called cellula. Interesting, that word also recalls another Latin word celare, and that means to conceal or hide. And from these origins came the word cell, and it made its literary debut in Hooke's 1665 book "Micrographia," which was a big best-seller at the time.
FLATOW: Well - so what did he actually use to look at these things called cells?
Dr. MARKEL: Well, he was looking at a thinly cut piece of cork as opposed to...
FLATOW: With a microscope?
Dr. MARKEL: With a microscope, a sort of a set of magnifying glasses. It didn't look quite like the microscopes today. But people were very interested in using lenses to both look at the stars as well as the things that were not visible to the naked eye right in front of them.
FLATOW: And why choose cork?
Dr. MARKEL: Well, because it was so firm, you know? One of the things that advanced later on in the 19th century was how to cut living tissue so that you wouldn't destroy it. And you have a very sharp knife or what's now called a microtome. But you could also introduce artifacts if you didn't cut it correctly, you know, little folds or tears, it wouldn't necessarily represent the living cell.
FLATOW: Right.
Dr. MARKEL: And so a cork is, you know, kind of wooden and fixed, and so he could use that and cut it very thinly and do his work.
FLATOW: So when was it noticed that even though you could look at a dead object like a piece of cork, how do we know that the same thing is going on in a living person or being?
Dr. MARKEL: Well, you know, things progress. You know, a few years later, you know, the famed Anton van Leeuwenhoek, a lens maker in Delft, he started looking at his microscope and saw the first living celled organism. It was an algae called spirogyra. He called them little animals.
But it wasn't really for another century and a half that doctors and scientists began looking at these in earnest. And there was a group of early 19th century German scientists, just cracker-jack scientists such as Theodor Schwann and Matthias Schleiden, Robert Remak, and most notably, Rudolph Virchow. And they developed a really novel notion, a revolutionary notion, called cell theory.
And this had two basic points: One that cells are the basic unit of all living things, as we just said. And another, a Latin phrase omnis cellula e cellula, which means all cells come from other cells just like it by means of cell division. And they could actually see the cells dividing under their scopes.
And that was very important because the prevailing theory at the time was something called spontaneous generation, that some living organisms could simply arise, de novo, from nonliving or, you know, living matter or what have you.
FLATOW: Right. And that got the ball rolling and that's where we are today.
Dr. MARKEL: Yeah. And then, you know, Rudolph Virchow kept talking about this. And not only talked about normal cellular function which was based on, you know, physical and chemical changes, but also that disease came from results of a deviation from that normal function. So that really started a whole new field of cellular pathology, that we could cure diseases on the cellular level, so to speak, that too, really flew in a smack of a lot of ideas, because the bodily humors...
FLATOW: Yeah.
Dr. MARKEL: ...were still much in vogue back then.
FLATOW: Well, Howard, thanks for the history. It's always great that we start out with a word and we get some great history from you.
Dr. MARKEL: Oh, thank you.
FLATOW: Thanks, have a good weekend. We'll see you back next month. Dr. Howard Markel is professor of history of medicine at the University of Michigan, and director of the Center for History of Medicine there in Ann Arbor.
Copyright © 2010 NPR. All rights reserved. Visit our website terms of use and permissions pages at www.npr.org for further information.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.