Note 101 — PREFATORY NOTE. (continued 2)

For proofs that the world is steadily working toward great discoveries as to the cause and prevention of zymotic diseases and of their propagation, see Beale's Disease Germs, Baldwin Latham's Sanitary Engineering, Michel Lévy, Traité d'Hygiène Publique et Privée, Paris, 1869. And for very thorough summaries, see President Barnard's paper read before Sanitary Congress in New York, 1874, and Dr. J. C. Dalton's Anniversary Discourse on the Origin and Propagation of Disease, New York, 1874.