 In 1865 he inherited the insect collections of Alexander and W. S. Macleay and leased Elizabeth Bay House, living there with his wife Susan.William John, like the Macleays who had lived in the house before him, was an ardent collector, sponsoring collecting expeditions including that of the "Chevert" to New Guinea in 1875, and broadening the collection from insects and marine invertebrates to encompass all branches of the natural sciences (such as birds and reptiles).Encouraging the study of botany, he was the first president of the Linnean Society of NSW (1874).