Australian Dictionary of Biography

Dennis Considen (d.1815), surgeon, was born in Ireland. He sailed with the First Fleet as surgeon in the Scarborough. At Sydney Cove Considen, like the principal surgeon, John White, studied the natural history of the country. He was prompted by utilitarian as well as by academic motives, for he used the products of indigenous plants to alleviate dysentery, scurvy and other diseases which scourged the settlement. Preparations from 'red gum' (kino from Eucalyptus and Angophora), 'yellow gum' (resin from grass trees Xanthorrhoea spp.), native sarsaparilla or sweet tea (Smilax glyciphylla Sm.) and the 'large peppermint-tree' (Eucalyptus piperita Sm.) were administered to the sick. In November 1788 Considen proclaimed himself to Sir Joseph Banks as the colony's pharmaceutic pioneer: 'If there is any merit in applying these & many other simples to the benefit of the poor wretches here, I certainly claim it, being the first who discovered & recommended them'. This claim was not without contemporary support. White also referred to these plant products and to the complaints for which they were considered beneficial, though it is uncertain whether White, Considen or the other surgeons actually discovered the medicinal qualities of individual species. Considen retained his interest in the therapeutic possibilities of Australian plants long after he left the colony, and as late as 1806 he asked D'Arcy Wentworth to send specimens of 'the Gums of the Country particularly the yellow and Red Gums as I wish to try some further Experiments of their Efficacy in Diseases'.

In November 1791, after a period on Norfolk Island working with Wentworth, Considen was relieved by William Balmain and he returned to Sydney. Next year he was granted leave because of ill health, sailed in the Kitty and arrived at Cork in February 1794. He served in the Army Medical Service as a hospital mate until October when he was commissioned as deputy-purveyor for service on the Continent. In August 1799 he was promoted purveyor but next March was put on half-pay. This allowance of about £200 a year enabled him both to study medicine at the University of Edinburgh, and to support 'with oeconomy' his two children. These he described in February 1804, in a letter to Wentworth, as his 'niece, poor Constance' and 'her brother Constantine'. The latter was born in New South Wales on 1 May 1793, the son of Dennis Considen and Ann Cowley, who had been transported for seven years for 'privately stealing' and had come out in the Lady Penrhyn in the First Fleet. Apparently both were natural children. When Balmain died in November 1803, Considen became co-executor of his will and co-guardian of his children.

On 24 June 1804 Considen graduated doctor of medicine with a thesis entitled De Tetano in which he referred to his discovery of eucalyptus oil. He returned first to London, 'at a loss where to practise' but soon went to County Clare, Ireland; from here he was almost immediately called to Cork to join an expedition bound for the Cape. Accordingly he was granted full pay once more from May 1805 until December 1808.

Considen maintained an interest in New South Wales and its natural history, and he may well have returned to the colony had not a request for a grant of land been refused by Governor Philip Gidley King. He kept in touch with his friends Thomas Arndell, George Johnston and D'Arcy Wentworth, but frankly declared his astonishment at the conduct of the last two when Governor William Bligh was overthrown. The few available glimpses of Considen's character indicate that he was a humane man with an earnest desire to do well in his profession. On 6 January 1812 he was admitted a licentiate of the College of Physicians. He died on 29 December 1815 and was well-nigh forgotten until 1904 when Joseph Maiden, government botanist of New South Wales, dedicated Eucalyptus consideniana to his memory in recognition of his pioneer work with eucalyptus oil.