openasocket says>"How on Earth does someone discover that? What possible series of events or hypotheses would lead someone to perform such an experiment?
Whoa! No one said that anyone "discovered that", or that "such an experiment" was performed. The article merely said that someone speculated that possibility. To further speculate on hearsay of mere speculation is not wise.
The "it is thought by some that" part is in regards to the circulation spreading pathogens. The OP asserted in definite terms that frogs were injected.
openasocket says>"How on Earth does someone discover that? What possible series of events or hypotheses would lead someone to perform such an experiment?
Whoa! No one said that anyone "discovered that", or that "such an experiment" was performed. The article merely said that someone speculated that possibility. To further speculate on hearsay of mere speculation is not wise.