Francis Bacon, Lord Chancellor of England, said that he took knowledge as his province-that is, as his department of government. The expression betrays his concern with bureaucratic organization to enable the creation of natural knowledge. By creating a division of cognitive labour, Bacon hoped to permit discoveries to a select elite at the head of this process, who could decide whether or not to share their knowledge with others, including the rulers of the people. The kind of knowledge that Bacon hoped to generate through his investigative procedures was aimed at producing unprecedented new phenomena, of a kind never before seen, yet which had lurked in the unrealized potential of matter. Sylva sylvarum contains ten so-called centuries of experimental or experiential items, that is, one hundred items per century. This format was also used for medical case histories, similarly empirical in form. The work, posthumously published in 1626, became very popular in England in the seventeenth century.