Observ. XVIII. Of the Schematisme of Texture of Cork, and of the Cells and Pores of some other such frothy Bodies. –OR– Biology Begins.

In 1665 the newly formed Royal Society published a collection of microscopic observations and drawings by Robert Hooke under the title “MICROGRAPHIA: or Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries thereupon”.  The book includes 60 observations presented to the Royal Society between 1663 and 1665, ranging from “Leeches in Vinegar” and “Bluish Mould on Leather” to “Fine Taffeta Ribbon” and “Poison fangs of Viper”.  In addition to detailed descriptions, the work includes 38 amazingly detailed renderings of what Hooke saw when he looked through his lens. 

Unbeknownst to Hooke, it was a short description and plain drawing half-way through the book that would eventually revolutionize our understanding of life itself.

Top: Hooke's skech of the "cells" he saw in thin slices of cork. Micrographia

“I Took a good clear piece of Cork, and with a Pen-knife sharpen’d as keen as a Razor, I cut a piece of it off, and thereby left the surface of it exceeding smooth, then examining it very diligently with a Microscope , me thought I could perceive it to appear a little porous…I with the same sharp Pen-knife, cut off from the former smooth surface an exceeding thing piece of it, and placing it on a black object Plate, because it was it self a white body, and the light on it with a deep plano-convex Glass, I could exceeding plainly perceive it to be all perforated and porous, much like a Honey-comb, but that the pores of it were not regular…these pores, or cells, were not very deep, but consisted of a great many little Boxes, separated out of on continued long pore, by certain Diaphragms”

Hooke goes on to conjecture that these airtight pores are responsible for the impermeability of the cork to water and air, while allowing the plasticity of shape that made Cork invaluable as a means of securing the mouths of bottles.  He also mentions that he has observed similar structures in “an Elder, or almost any other tree…hollow stalks of several other Vegetables: as of Fennel, Carrets…Fearn, some kinds of Reeds, &c”.

Hooke didn’t even begin to imagine how this observation would change our understanding of the physical world, but he did recognize that he has discovered something utterly new. 

“I…discern’d these (which were indeed the first microscopical pores I ever saw, and perhaps, that were ever seen, for I had not met with any Writer or Person, that had made any mention of them before this), but me thought I had…the discovery of them”

Hooke, R.  Micrographia. (1665) 112-116.

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