11 January 1887, the day medicine changed: Joseph Grancher's defense of Pasteur's treatment for rabies.

The Pasteur treatment for rabies is generally seen in terms of a triumphant penetration of laboratory science into clinical medicine. Similarly, the debates challenging the Pastorians have been interpreted as retrograde and inevitably vain efforts by a few disgruntled clinicians to resist scientific progress. This article revises the standard account by showing that the defenders of Pasteur perceived a serious threat to their enterprise and acted expeditiously to counter a potential crisis by adopting clinical strategies and tactics to argue for the relative safety of their method and to account for the rare failures resulting in deaths. An extensive unpublished source, the correspondence of Dr. Joseph Grancher with Pasteur, reveals this physician's leading role in successfully orchestrating the defense of Pasteur's antirabies method in January 1887 in the National Academy of Medicine. In responding to Dr. Michel Peter's accusations that the method could be dangerous and had been fatal in certain cases, Grancher invoked notions of risk inherent in all medical therapy, along with individual variability and predisposition to disease. Grancher's unpublished correspondence, supplemented by other manuscript letters, permits a textured understanding of the urgency experienced by Pasteur's team and their interactions as they worked out a strategy to defend their pioneering entry into human medicine. The suppression of autopsy evidence in one fatal case is apparent. More important, the strategy of the Pastorians implied a complementarity between the "clinic" and laboratory science, rather than any opposition.