In May and June 1623, he passed his examination with the College of Physicians of London, and was ordered to become incorporated at one of the English universities.
[2] By 16 December 1626, Cademan was appointed physician in ordinary to Queen Henrietta Maria.
On 4 August 1638, on consideration of a petition to government presented in March previous, Sir Theodore de Mayerne, Cademan, and others distillers of spirits and makers of vinegar in London, were incorporated as "Distillers of London".
To this petition Mayerne, Brouncker, and Cademan replied, and the undertaking was allowed to proceed, and in 1638 was published The Distiller of London, compiled and set forth by the special Licence and Command of the King's most Excellent Majesty for the sole use of the Company of Distillers of London, and by them to bee duly observed and practiced.
It is explained in the preface as book of rules and directions concerning distillation of strong waters and making vinegars.
[2] In 1649 Cademan was chosen anatomy lecturer to the College of Physicians, but was lax in the post.
[2] Cademan was physician to Francis Russell, 4th Earl of Bedford, of whose death he wrote an account in a pamphlet of six pages, The Earle of Bedford's passage to the Highest Court of Parliament, 9 May 1641, about tenne a clock in the morning (1641).