Since microbes were not known until the Early Modern period, they appear in earlier literature indirectly, through descriptions of baking and brewing. Only with the invention of the microscope, as used by Robert Hooke in his 1665 book Micrographia,[1] and by Antonie Van Leeuwenhoek in the 1670s,[2] the germ theory of disease, and progress in microbiology in the 19th century were microbes observed directly, identified as living organisms, and put to use on a scientific basis.[3] The same knowledge also allowed microbes to appear explicitly in literature and the arts.[4]