Monitoring the stable at the Pasteur Institute.

Diphtheria serum production in France was dominated by the Pasteur Institute, which equipped a facility at Garches to produce the antitoxin on a large scale. This article treats the background to the founding of this facility, as well as its day-to-day functioning around 1900. The treatment integrates an examination of the practical undertaking of serum production by the Pasteur Institute with an analysis of the popular perception of the Institute and the mixed financing of the whole venture. We particularly emphasize the "industrial" features of this manufacturing process that involved living units of production, showing how bioassays influenced the destiny of the animals producing the serum. Finally, we argue that this monitoring of the horses, seen as serum-producing units, also provided information on the diseases the sera were intended to treat.