Robert Hooke read his paper about his microscopic observations and methods
At the Royal Society's meeting on March 14/24 (O.S./N.S.), Hooke read all or part of what he had written for Microscopium, published that year.
Birch's History, vol. III p. 393
Mr. HOOKE read a discourse of his own, being an account of his observations, which in prosecution of Mr. LEEWENHOECK'S discoveries he had made of the small worms in pepper-water, and in the steeping of several other liquors, as of barley, wheat, oats, anniseeds, coffee, etc. as also of sugar, alum, blood, milk, fat, ligaments, muscles, etc. and together herewith he discovered the several ways and contrivances by which he made those obfervations; and therein shewed how easily and apt such persons are to be deceived by the appearances of these transparent bodies through a microscope, who are not aware of certain properties of transparent bodies, especially such as are peculiar to substances of such small bulk. And for the avoiding and preventing all these inconveniences, he shewed several ways and expedients, without which no true discovery could be made, and by the help of them they were very easily made.
Some of those mentioned by him were glass plates, and plates of Muscovy glass, particular kinds of light, the immersing the bodies in waters and other liquors, the squeezing bodies between two glass plates, the stretching and squeezing others with a kind of tongues, etc. whilst they are looked upon in a convenient light by the eye.
After which he shewed the method, by which he made two sorts of microscopes, and the conveniences and inconveniences of both these. The first was a single microscope made by "a small globule of glass, by means of which, with very little or no difficulty, any object might be prodigiousiy magnined.. He also explained how the globule was made out of a thread of glass, and how that glass thread and small glass-canes were made.
The second was a double microscope consisting of two glasses, whereby many observations might be more conveniently made than with the single one. He then explained how, by the help of these, the parts of a muscle, fibre, tendon, ligament, etc. might be examined: and to verify this by experiment, he produced a small part of the ligament of the neck of a sheep, and shewed it to consist of an infinite number of exceedingly small threads, four hundred of which would scarce make the bigness of one single hair of a man's head. But as to the fibres of a muscle, he affirmed them to be very different, which he would some other time produce.
