The vein usually opened in the arm of a patient was resorted to for the purpose of transfusion; into this a small tube was placed in a perpendicular direction; the same vein was then opened in a healthy individual, but more frequently in an animal, into which another tube was forced in a reclining direction; both small tubes were then slid into one another, and in that position the delicate art of transfusion was safely performed. When the operation was completed, the vein was tied up in the same manner as on blood-letting. Sometimes a quantity of blood was drawn from the patient, previously to the experiment taking place. As few persons, however, were to be found, that would agree to part with their blood to others, recourse was generally had to animals, and most frequently to the calf, the lamb, and the stag. These being laid upon a table, and tied so as to be unable to move, the operation was performed in the manner before described. In some instances, the good effects of these experiments were evident and promising, while they excited the greatest hopes of the future improvement and progress of this new art. But the unceasing abuses practised by bold and inexpert adventurers, together with the great number of cases, which proved unsuccessful, induced the different governments of Europe to put an entire stop to the practice, by the strictest prohibitions. And, indeed, while the constitutions and mode of living among men differ so materially as they now do, this is, and ever must remain, an extremely hazardous and equivocal, if not a desperate remedy. The blood of every individual is of a peculiar nature, and congenial with that of the body only to which it belongs, and in which it is generated. Hence our hope of prolonging human life, by artificial evacuations and injections, must necessarily be disappointed. It must not, however, be supposed, that these, and similar pursuits during the ages of which we treat, as well as those which succeeded, were solely or chiefly followed by mere adventurers and fanatics. The greatest geniuses of those times employed their wits with the most learned and eminent men, who deemed it an object by no means below their consideration.