Hortus Siccus translates as ‘dried garden’ and this object is a book of pressed plant specimens. Single sheets of specimens (herbarium sheets) are relatively common, but sheets bound into huge books like this are far rarer.
This example, dated 1718, was a scientific reference book of its day. An inscription reveals that its first owner was John Bateman, former President of the College of Physicians. He gifted it to the College, which in turn donated it to the Society in 1926.
Unlike the herbarium sheets in the Society’s collection, some of the specimens are accompanied by pressed butterflies — presumably species which fed on that particular flower.