William Ian Beardmore Beveridge (1908-2006) was an Australian veterinarian with a long, distinguished career1. Besides many papers and books on veterinary medicine, he also wrote 2 books on how scientists work and how scientific discoveries are made.
The 1st book, The Art of Scientific Investigation, was published in 1950, followed by a revised edition in 1957. The 2nd book, Seeds of Discovery, came out in 1980. It is one of my all-time favorite books. I've had a copy since 1982 and still pick it up every now and then and re-read parts of it.
Recently, I bought a cheap ex-library copy of The Art of Scientific Investigation (2nd ed.) and started reading it. It is basically a compilation of mostly anecdotal accounts of how various scientists worked and made their discoveries. Beveridge put a great emphasis on the significance of chance in science.
Probably the majority of discoveries in biology and medicine have been come upon unexpectedly, or at least had an element of chance in them, especially the most important and revolutionary ones.I am not sure if that's true. Also, one can argue that everything everyone does has an element of chance in it. In retrospect, the schools we've been to, the people we've met, the things we've done were all predetermined by chance events to some extend. So, it's not surprising that chance plays a part also in scientific discoveries.
Nevertheless, Beveridge was careful to point out that not every lucky scientist ends up with a groundbreaking discovery.
The role of chance is merely to provide the opportunity and the scientist has to recognize it and grasp it.This, of course, remind us of a saying attributed to Louis Pasteur: "In the field of observation, chance favors only the prepared mind." This is indeed true. If a scientist's mind is not always ready to grasp the significance of an unusual observation or an unexpected experimental result, then chance will favor someone else.
Beveridge's beverage! (I just like saying that).
1Fenner, F. 2007. William Ian Beardmore Beveridge. 1908-2006. Australian Veterinary Journal, 85:1-2.