Samuel Alexander was employed as Surgeon-Superintendent on the convict ship Almorah in 1820.
He kept a Medical Journal from 24th June 1820 to 5th January 1821.
Samuel Alexander joined the Almorah at Deptford where she was being fitted for the reception of the convicts. On 11 July they sailed down the river bound for Cork where the men were to be embarked. The Almorah departed the Cove of Cork bound for Australia on 24 August 1820.
Ulcers were troublesome to the convicts in the first part of the voyage and were to be attributed to the prisoners entertaining an idea that if they could get their legs ulcerated, their irons would be taken off; however by undeceiving the convict on this head, and pursuing a strict plan of treatment, the ulcers were soon overcome.
Samuel Alexander ensured that cleanliness and ventilation in the prison were maintained as best as possible. The prisoners were kept occupied by his plan of appointing a particular duty each day such as scrubbing cloths, mustering, airing bedding etc. A school was also established amongst the prisoners. 
The Almorah arrived in Port Jackson on 22 December 1820. 
Samuel Alexander was planning to leave the colony at the earliest opportunity and requested claims to be presented in January 1821.
 Sydney Gazette 23 December 1820
 Ancestry.com. UK Royal Navy Medical Journals, 1817-1857