Blood-letting was practiced for a wide variety of conditions from the 5th century BC, but infusing blood from one human being into another was not documented until December 22, 1818.1 Therapeutic bleeding was based on Hippocrates’ precept that illness was caused by imbalances among the four humors, phlegm, blood, yellow bile, and black bile that comprised all living matter. In the absence of illness, lust and arrogance were attributed to a preponderance of blood, so bleedings were also performed for behavioral adjustment and paradoxically, to restore vigor that had lapsed with aging. Similar rationales prompted many early transfusions, anticipating replacement of bad blood with good blood would be reinvigorating and that a donor’s demeanor and temperament would gain expression in the recipient. James Blundell (1790-1878), an obstetrician and physiologist at Guy’s Hospital, performed his seminal human-to-human transfusion on September 25, 1818. He had extensive experience with homologous and heterologous (human) canine transfusions, showing the latter to be eventually lethal. Blundell intended to revitalize a 40-year-old man suffering inanition. He began by having a surgeon insert and maintain a cannula in the patient’s cephalic vein. Blundell then serially lanced the arm veins of several willing observers, allowing approximately 45 mL to drip into a cup to be aspirated with paraffin lined syringes for injection into the indwelling cannula. Ten such transfers were made over a period of 40 minutes. The patient seemed to gain strength for 2 days but withered on the third to die 56 hours after the injections. Necropsy revealed an obstructing distal gastric cancer. Blundell subsequently achieved good results with his multiple syringe technique, particularly for postpartum hemorrhage, typically using cannulae in both the donor and recipient veins. Direct transfusion requires donor-recipient proximity and relies on quick transference to mitigate clotting. Transfusion from a donor artery to a recipient vein occurs spontaneously upon connection, whereas, vein-to-vein direct transfusion requires energizing, which can be accomplished by gravity, pumping, or withdrawal into a delivery device for prompt infusion (Fig 1).2 Authors have occasionally labeled the last as indirect transfusing, but “indirect” should be reserved for procedures that do not require immediate donor presence and include physical (defibrination) or chemical coagulation control for storage, no matter how brief. Fig 1 A, Blundell’s2 Gravitator supported by an overturned chair on the recipient’s bed; B, Surgical resident Michael DeBakey’s hand-cranked roller pump (A simple continuous flow blood transfusion instrument. New Orleans Med Surg J 193; ... Nobel Suydam Rustum Maluf’s3 History of Blood Transfusion, written in 1954, as a J. Bently Squire urology resident in New York, portrays the muddling allusions and uncertainties that preceded 50-year-old William Harvey’s 1628 publication of “Exercito Anatomica de Motu Cordis et Sanguinis in Animalibus.” These ranged from Ovid (43bc-18ce) relating a story of exsanguination and repletion with a “rich elixir,” to Saxon, physician-chemist Andreas Libavius’s vivid 1615 description of an artery-to-artery transfusion from a healthy person into a cachectic old man through connecting silver cannulae that imparted the “fountain of life” and drove away “all faintness.” Libavius had not actually performed the procedure, but his artery-to-artery connection reflected the prevailing belief that blood sloshed back and forth in arteries fortified by pulses of air, accounting both for their emptiness after death and a more temperate to-and-fro movement in veins.