It may seem incredibly strange that the earliest transfusions used animals as donors. But this actually makes good sense, in a way. The first transfusionists were interested in finding the best and purest blood that they could use in their experiments. Animals fit the bill.
When’s the last time you’ve seen a dog speak? Or heard a cow swear? Or a lamb drink? The thought was that animals lived purely. They did not corrupt their blood with foul matter, like humans did.
Also, animals were – so they thought – expendable. Why risk the life of two human beings in these risky experiments when you could pluck animal off the street or have a local butcher bring one in?
Denis’ very first blood experiment on humans was performed on a feverish boy. The second on a butcher, likely the one who brought the lamb in for the first experiment. Both survived.
The next human transfusion was performed in England. But the English had shifted course. They focused their efforts on a mentally-ill man named Arthur Coga. Coga was well-educated and spoke fluent Latin. But there was something off about him. “Cracked in the head,” as a contemporary wrote.