In 1835 he left Newfoundland for Compton, Lower Canada where he farmed unsuccessfully for three years, originally in an attempt to establish a commune with two of his religious friends. Nevertheless, the experience deepened his love for natural history, and locals referred to him as "that crazy Englishman who goes about picking up bugs. Gosse then taught briefly in central Alabama, studying and drawing the fauna and hating everything "he saw and everything he heard" about slavery.
Gosse opened a "Classical and Commercial School for Young Gentlemen" while keeping detailed records of his microscopic investigations of pond life, especially cyclopidae and rotifera. He also began to preach to the Wesleyan Methodists and lead a Bible class. Nevertheless, in 1842, he became so captivated by the doctrine of the Second Coming of Christ that he severed his connection with the Methodists and joined the Plymouth Brethren. These dissenters emphasized the Second Coming while rejecting liturgy and an ordained ministry—although they otherwise endorsed the traditional doctrines of Christianity as represented by the creeds of the Methodist and the Anglican Church.
In 1843, Gosse gave up the school to write a An Introduction to Zoology for the Society for Promoting Christian Knowledge (SPCK) and to draw some of the illustrations. Writing the work inspired him to further his interest in the flora and fauna of the seashore and also revealed him to be a determined creationist, although this position was typical of pre-Darwinian naturalists.
In October 1844 Gosse sailed to Jamaica, where he served as a professional collector for the churlish dealer Hugh Cuming. Although Gosse worked hard during his eighteen months on the island, he later called this period his "holiday in Jamaica. Gosse's study specialized in birds, and Gosse has been called "the father of Jamaican ornithology." With no racial prejudice, he easily hired black youths as his assistants, and his Jamaican books are full of praise for one of them, Samuel Campbell. For Christian companionship he enjoyed the company of Moravian missionaries and their black converts and preached regularly to the Moravian congregation.
On his return to London in 1846, he wrote a trilogy on the natural history of Jamaica including A Naturalist's Sojourn in Jamaica (1851), which was "written in a congenial style and firmly established his reputation both as a naturalist and a writer.
Gosse penned a succession of books and articles on natural history, some of which were (in his own words) "pot-boilers" for religious publications. (At the time, accounts of God's creation were considered appropriate Sabbath reading for children.) As L. C. Croft has written, "Much of Gosse's success was due to the fact that he was essentially a field naturalist who was able to impart to his readers something of the thrill of studying living animals at first hand rather than the dead disjointed ones of the museum shelf. In addition to this he was a skilled scientific draughtsman who was able to illustrate his books himself.
Suffering from headaches, perhaps the result of overwork, Gosse and his family began to spend more time away from London on the Devon coast. Here along the sea shore Gosse began serious experimentation with ways to sustain sea creatures so that they could be examined "without diving to gaze on them." Although there had been attempts to construct what had previously been called an "aquatic vivarium" (a name Gosse found "awkward and uncouth"), Gosse published The Aquarium in 1854 and set off a mid-Victorian craze for household aquariums. The book was financially profitable for Gosse, and "the reviews were full of praise" even though Gosse used natural science to point to the necessity of salvation through the blood of Christ. In 1856 Gosse was elected a Fellow of the Royal Society, which, because he had no university position or inherited wealth, gave him "a standing he otherwise lacked.
A few months before Gosse was honored, his wife discovered that she had breast cancer. Rather than undergo surgery (a risky procedure in 1856), the Gosses decided to submit to the ointments of an American doctor, Jesse Weldon Fell, who if not a charlatan, was certainly on the fringe of contemporary medical practice. After much suffering, Emily Gosse died on February 9, 1857, entrusting her husband with their son's salvation and thus perhaps driving Gosse into "strange severities and eccentric prohibitions.
In what Stephen Jay Gould has called "glorious purple prose, Gosse argued that if one assumed creation ex nihilo, there would necessarily be traces of previous existence that had never actually occurred. "Omphalos" is Greek for "navel", and Gosse argued that the first man, Adam, did not require a navel because he was never born; nevertheless he must have had one, as do all complete human beings, just as God must have created trees with rings that they never grew. Thus, Gosse argued that the fossil record—even coprolites—might also be evidence of life that had never actually existed but which may have been instantly formed by God at the moment of creation.
The general response was "as the Westminster Review put it, that Gosse's theory was 'too monstrous for belief.'" Even his friend, the novelist Charles Kingsley, wrote that he had read "no other book which so staggered and puzzled" him, that he could not believe that God had "written on the rocks one enormous and superfluous lie for all mankind. Later mocking journalists would snigger that God had apparently hidden fossils in the rocks to tempt geologists to infidelity.
Omphalos sold poorly and was eventually rebound with a new title, Creation, "in case the obscure one had had an effect on sales." The problem was not with the title, and in 1869 most of the edition was sold as waste paper.
By this time Gosse and his son had moved permanently from London to St Marychurch, Devon. (Gosse refused to use the "St" and even gave his address as Torquay so as not to have anything to do with the "so-called Church of England.") He soon became the pastor and overseer of the Brethren meeting, at first over a stable but shortly, under Gosse's preaching and peacemaking, in finer quarters—which he perhaps financed himself.
During this period, Gosse made a special study of sea anemone (Actiniae) and in 1860 published Actinologia Britannica. Reviewers especially praised the color lithographs made from Gosse's watercolors. The Literary Gazette said that Gosse now stood "alone and unrivalled in the extremely difficult art of drawing objects of zoology so as to satisfy the requirements of science" as well as providing "vivid aesthetic impressions.
In 1860 he also met and married a Quaker spinster, Eliza Brightwen (1813–1900), a kindly, tolerant woman who shared Gosse's intense interest in both natural history and the well-being of his son. Gosse's second marriage was as happy as his first. In 1862 he wrote that Eliza was "a true yoke-fellow, in love, in spirit and in service.
By this time Gosse was "very comfortably off" with the earnings from his books and dividends from his investments, and in 1864 Eliza received a substantial legacy which allowed Gosse to retire from his career as a professional writer and live in "congenial obscurity. The Gosses lived simply, invested some of their income and gave more away to charity, especially to foreign missionaries, including ones sent to the "Popish, priest-ridden Irish.
To Gosse's great grief, his son rejected Christianity—though almost certainly not as early or as dramatically as Edmund portrayed the break in Father and Son. Nevertheless, Henry sponsored the publication of Edmund's early poetry, which gave the younger man entrée to new friends of literary importance, and the two men "came out of the years of conflict with their relationship wary but intact. Henry and Eliza welcomed Edmund's wife to the family and enjoyed visits with their three grandchildren.
Meanwhile, the ever active Gosse published a book on the fertilization of orchids and exchanged a number of letters on the subject with Darwin. His penultimate enthusiasm was with the genitalia of butterflies about which he published a paper in the Transactions of the Linnean Society But before his death he returned to rotifera, much of his research appearing in a two-volume study by another zoologist.
His wife recalled that Gosse's final illness was triggered by his enthusiasm to adjust his telescope at an open window on a winter night. Gosse had prayed regularly that he might not taste death but meet Christ in the air at his Second Coming, and he was bitterly disappointed when he realized that he would die like everyone else.
Even a modern editor of F&S has rejected this portrait of Philip Henry Gosse on the grounds that his "writings reveal a genuinely sweet character. But the biographer of both Gosses, Ann Thwaite, has established just how inaccurate Edmund's recollections of his childhood were, that Edmund indeed, as Henry James remarked, had "a genius for inaccuracy. Although Edmund went out of his way to declare that the story of F&S was "scrupulously true," Thwaite cites a dozen occasions on which either Edmund's "memory betray[ed] him—he admitted it was 'like a colander'"—or he "changed things deliberately to make a better story.