PREVENTIVE INOCULATION.

A lecture that should receive a great deal of attention from the world of medicine is the Croonian lecture on "Preventive Inoculation," recently delivered by M. Roux, in behalf of M. Pasteur. It is almost eight years since the great scientist laid before the members of the International Medical Congress assembled in London an account of the researches, carried on in his laboratory, on preventive inoculations for chicken cholera and splenic fever. Has the work then begun fulfilled its promise? What place have the principles that it involved in the science of to-day?

In speaking of preventive inoculation we need not stop to consider the great discovery of Jenner. He showed that it is possible to protect ourselves from a dreaded disease by inoculation with a trivial one; but he gave no general method leading to the prevention of other infectious diseases. The discovery of the power of artificially attenuating—or