John Murray (1778-1820) was a public lecturer and writer on chemistry and geology. After attending the University of Edinburgh he became a popular public lecturer on chemistry and pharmacy. He was also a prolific writer of chemistry textbooks which were widely used in British universities. This popular volume, first published anonymously in 1802, contains Murray's critical response to John Playfair's volume Illustrations of the Huttonian Theory of the Earth, also published in 1802 and re-issued in this series. In this volume Murray clearly describes both the competing Huttonian and Neptunian (also known as Wernerian) theories of rock formation. Using much of the same geological evidence as Playfair, Murray also objectively analyses the theories' claims through rock and fossil formations and concludes in support of the Wernerian theory. This valuable volume explores one of the major geological controversies of the period and illustrates the main contemporary criticisms of Hutton's work.