John Atherstone, son of Hugh Atherstone and his wife Ann Green, practised medicine in Nottingham, England, and was resident house surgeon at Guy's Hospital, London, for a year before emigrating to the Cape of Good Hope with a party of 1820 settlers lead by his brother-in-law. After being licensed to practise in the Cape Colony as a surgeon in April 1820 he became district surgeon of Uitenhage, but it proved difficult to make a living there and after a year he moved to Cape Town. In August 1822 he was appointed district surgeon of Albany and set out for Grahamstown, but turned back on hearing that there was no house available for him there. He remained in the mother city for the next six years, building up a large practice. During this period he delivered a series of public lectures on aspects of physics and chemistry - the first such lecture series at the Cape it seems - which included a number of experiments to illustrate the subject matter. One of these demonstrated a small but working steam engine, to the delight of the audience. Some of the apparatus required for the experiments was not available in the colony and was specially made for him in Cape Town. He also explained at least one of his topics, namely latent heat, in a letter to the press in response to questions from a member of the public. In April 1826 he drew the attention of the British government to the need for a public school where "natural and experimental philosophy and chemistry" would be taught, indicating his willingness to lecture at such an institution, but nothing came of it. His interests also included horticulture, as he was a member of the Cape of Good Hope Horticultural Society, formed in December 1826.
In 1828 Atherstone was again appointed district surgeon of Albany, succeeding Dr Alexander Cowie. He settled in Grahamstown, where he set up a private practice in addition to his official duties and became the leading medical practioner. In 1831 he and the district surgeon of Graaff-Reinet, Dr T. Perry, applied widespread vaccination in and around Philipolis to combat a deadly small-pox epidemic among the Griquas. As district surgeon Atherstone was the only doctor in Grahamstown allowed to vaccinate the public against small-pox and when he delegated this duty to his son Dr William G. Atherstone* during a brief absence from Grahamstown in 1840 the latter was fined 500 rix-dollars. In 1835 John bought and ran a private hospital in Grahamstown which later became the Albany General Hospital. The respect in which he was held by his colleagues is shown by a case in 1849 when a child had a date stone stuck in her throat. Three medical practitioners were unsure how to proceed with an operation to remove it and called in John Atherstone for advice. He convinced them that a thracheotomy was called for, and with their assistance carried it out successfully.
Atherstone retained his interest in public life during his long time in Grahamstown. Soon after his arrival, in May 1829, a reading society was formed in the town and he was elected a member of its first management committee. In 1848 he took a leading role in founding the Grahamstown Philomathic Society, a debating society the object of which was the cultivation of rhetoric, literature, and general knowledge. Atherstone chaired its first meeting and was requested to act as the society's secretary and treasurer. He also introduced its first debate, the topic being "What does the most to make the orator - knowledge, genius, or art?"
In 1840 John's son William Guybon succeeded him as district surgeon, and gradually also as the most prominent medical practitioner in Grahamstown. John was however still the vaccinating doctor in 1845. He served in the Seventh Frontier War of 1846-1847, and went into semi-retirement on Table Farm. He was a supporter of Eastern Province separatism and was nominated to the Cape Legislative Council, but resigned his seat. In May 1855 he sustained a spinal injury in a cart accident in Grahamstown and died a few days later. He married Elizabeth Damant in 1811 and they had three sons and five daughters.