The origins and early days of the Three Rs concept.

Some questions are answered concerning the origins of the Three Rs (Replacement, Reduction, Refinement) concept in relation to animal experimentation, expounded 50 years ago by Russell and Burch in The Principles of Humane Experimental Technique, by reference to some key publications and to correspondence in the W.M.S. and Claire Russell Archive, which is currently being established at the University of Nottingham. Some insight is also given into the relationship between Russell and Burch, the first use of "alternatives" in the Three Rs context, and the background to the publication of the book. 2009 FRAME.