Professor Ralph Frerichs of UCLA has created this masterful site dedicated to exploring the life and work of John Snow, an individual who is perhaps best known for determining how cholera is transmitted. Along with offering a biography of Dr. Snow, the full-text version of his seminal work, "On the Mode of Communication of Cholera" is included. Best of all, Professor Frerichs has scanned the all-important maps that Dr. Snow created to document the spread of cholera within London, and they are featured here as well. Professor Frerichs has also added other information related to the historic debates about its spread and nature, along with competing theories of cholera and an extended discussion of the removal of the Broad Street pump, which effectively ended the threat of cholera in that part of London. Along with providing a great deal of material about the nature and history of public health investigations, this site is a good example of how to present a broad range of historical material on the Internet effectively.