Mr. E. E. Austen, of the British Museum, has been good enough to undertake the translation of my book on "Venoms." For the presentation of my work to the scientific public in an English dress I could not have hoped to find a more faithful interpreter. To him I express my liveliest gratitude for the trouble that he has so kindly taken, and I thank Messrs. John Bale, Sons and Danielsson for the care they have bestowed upon the preparation of this edition. Institut Pasteur de Lille, A. Calmette, M.D. June 17, 1908.iv