While still trading as a jeweller and goldsmith, in 1801, he published a descriptive catalogue of the works of art, armoury, objects of natural history, and other curiosities in the collection, some of which had been brought back by members of James Cook's expeditions.

[1][2] In 1810, Bullock figured briefly in a law case concerning Sarah Baartman, a Khoikhoi woman brought to England for purposes of exhibition as the "Hottentot Venus".

Bullock had been approached by Alexander Dunlop, the army surgeon responsible for Baartman's arrival in England, but had declined to be involved in the proposed show.

[1][5] Bullock bought land on the bank of the Ohio River from Thomas D. Carneal where he proposed to build a utopian community named Hygeia (a Greek word meaning health) laid out by John Buonarotti Papworth.

The speculation was not a success, although some people, including Frances Trollope, took part; Bullock sold the land to Israel Ludlow, Jr. in 1846.