A book, apparently, written by Asimov (this being the fourth edition) which goes over all of scientific knowledge briefly, divided into the two sections The Physical Sciences and The Biological Sciences.
Added it to The List on February 2011, without giving a reason. Bought it while on holiday in Northumberland from Barter Books, a massive second hand book shop in Alnwick, for £3.60, on the 26th of August 2011. Read the beginning that day.