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Micrographia, published by the Royal Society in 1667, he records his 

 numerous " observations made on minute bodies of very varied kinds 

 by magnifying glasses." The work is illustrated by fine plates. 



The microscope he used was a compound microscope, and was 

 about three inches in diameter, seven long, and provided with four 

 draw tubes. It had three glasses — an object glass, a middle glass, 

 and a deep eyepiece. Dr. Hooke also described a simple method of 

 estimating the magnifying power of a compound microscope. 



" Robert Hooke, the son of a clergyman, was born at Freshwater, in the Isle of 

 Wight, on 18th July, 1635. He displayed from his earliest years a ready apprehension, 

 a strong memory, and a surprising invention. He took his degree of M.A. at Oxford in 

 1660. While at the University he became conspicuous by his mechanical inventions; 

 and the air pump which he contrived for Mr. Boyle gave him so much celebrity, that we 

 find his name included in the first list of members, chosen by the President and 

 Council of the Royal Society, after they had received their Charter from Charles II. 

 Soon after he was appointed Curator to the Society, and his business was to contrive and 

 exhibit experiments at the meetings of that illustrious body." 



In 1677 he succeeded Mr. Oldenburg as secretary of the Society. 

 It seems that " towards the end of his life his temper, which was 

 always bad, became intolerable. In his person he was small and 

 deformed, but he was exceedingly active." (Thomson's History of 

 the Royal Society, p. 332, 1812.) 



"An account of an Experiment made by Mr. Hooke of preserving Animals alive by 

 blowing through their Lungs with Bellows. — October 24th, 1667. I did heretofore give 

 this illustrious Society an account of an experiment I formerly tried of keeping a dog 

 alive after his thorax was all displayed by the cutting away of the ribs and diaphragm, 

 and after the pericardium' of the heart was also taken off. But divers persons seeming 

 to doubt of the certainty of the experiment (by reason that some trials made of this 

 matter by some other persons failed of success), I caused at the last meeting the same 

 experiment to be shown in the presence of this noble company, and that with the same 

 success as it had been made by me at first ; the dog being kept alive by the reciprocal 

 blowing up of his lungs with bellows, and they suffered to subside, for the space of an 

 hour or more after his thorax had been so displayed, and his aspera arteria cut off just 

 below the epiglottis, and bound on upon the nose of the bellows. 



" And because some eminent physicians had affirmed that the motion of the lungs 

 was necessary to life, upon the account of the promoting of the circulation of the blood, 

 and that it was conceived the animal would immediately be suffocated as soon as the 

 lungs should cease to be moved, I did (the better to fortify my own hypothesis of this 

 matter, and to be the better able to judge of several others) make the following 

 additional experiment, viz. : — 



" The dog having been kept alive (as I have now mentioned) for above an hour, in 

 which time the trial had been often repeated, in suffering the dog to fall into convulsive 

 motions by ceasing to blow the bellows, and permitting the lungs to subside and lie still, 

 and of suddenly reviving him again by renewing the blast, and consequently the motion 

 of the lungs ; this I say having been done, and the judicious spectators fully satisfied of 

 the reality of the former experiment, I caused another pair of bellows to be immediately 

 joined to the first by a contrivance I had prepared, and pricking all the outer coat of 

 the lungs with the point of a very sharp penknife, this second pair of bellows was moved 

 very quick, whereby the first pair was always kept full and blowing into the lungs, by 

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