The first transfusion of blood into a human was performed by Denis on June 15, 1667; he transfused lamb’s blood into a youth. For a partial translation, see Geoffrey Keynes’s Blood transfusion (Bristol, 1949) 14-15. Denis also wrote: “a letter concerning a new way of curing sundry diseases by transfusion of blood”, which was published in some copies of Phil. Trans., 1667, 2, 489-504; for a reprint and a paper on the subject, see A. D. Farr, Med. Hist., 1980, 24, 143-62.