’ In my book concerning the motion of the heart and blood in creatures, I only chose out those things out of my many other observations, by which I either thought that errors were confuted, or truth was confirm'd; I left out many things as unnecessary and unprofitable, which notwithstanding are discernable by dissection and sense; of which I shall now add some in few words, in favour of those that desire to learn.’ (William Harvey, Exercitatio altera, 1649. Nonesuch edition, 1928, p. 147.)

BIBLIOGRAPHICAL PREFACE

HARVEY'S first treatise caused, as he no doubt expected, a great stir among the philosophers and anatomists of his time. As already seen in the preceding section, several of the reprints of his tract were accompanied, paragraph by paragraph, by the ‘refutations’ of those who disliked to acknowledge that accepted authority was at fault. Harvey was subjected to misrepresentation and abuse, but in spite of every provocation he maintained silence for twenty-one years, secure in the possession of the truth. At length in 1649 he chose to publish a small book containing two essays addressed to John Riolan the younger, professor of anatomy at Paris. Riolan was one of the most famous anatomists of his time, and so was perhaps regarded by Harvey as specially worthy of an answer, although by no means all his earlier opponents had been lesser lights. Riolan had expressed his views regarding the circulation of the blood in a book entitled: Opufcula anatomica nova. Luœ nunc primum in lucem prodeunt. Inftauratio magna Phyficœ & Medicine, per novam Doctrinam de Motu Circulatorio Sanguinis in Corde. Londini, Typis Milonis Flefher. MDCXLIX.

Harvey's book was published in 1649 by Roger Daniel at Cambridge and by Arnold Leers at Rotterdam. Both books are rare, so rare that the very existence of the Cambridge edition was doubted by Mr Charles Perry Fisher when compiling his list in 1912, but now I am able to record twelve copies of one and thirteen of the other. The Cambridge edition has the greater bibliographical interest, as the first title-page was cancelled, and the substituted title-page is found in two forms. No example of the original title-page is known at present, but the copy of the book in the Bodleian Library shows part of its left-hand edge still remaining.