Born on December 17th, 1816, the son of Staff Surgeon Thomas Docker. He was gazetted Assistant Surgeon to the 54th Foot on December 29th, 1840, and was transferred to the 60th Foot on June 6th, 1845, and to the 2nd Foot on January 15th, 1847. He was promoted Surgeon to the 5th Foot on March 14th, 1851, and joined the Staff (2nd Class) on September 18th, 1857. He was transferred to the 7th Foot on October 23rd, 1857, and to the 18th Dragoons on August 13th, 1858. He was again placed on the Staff on September 4th, 1860, and was promoted Staff Surgeon on December 29th of that year. He retired on half pay, with the honorary rank of Deputy Inspector-General of Hospitals, on March 2nd, 1866. During his long service in the Army in India and Ceylon, Docker revived an old treatment of tropical dysentery with large doses of ipecacuanha, by which the enormous mortality from that disease was greatly diminished. In his lectures before the Army Medical School, Netley, Surgeon General William Campbell Maclean used yearly to eulogize Docker's practice as one that had done more to lessen human suffering wherever this disease prevails than any other plan of treatment our art has been able to suggest. In the year 1883, out of a force of 13,000 men, 500 cases of dysentery were treated with only two deaths. In the pre-sanitary age it was known that one regiment, with an average strength of 1098 men, had 2497 admissions and 104 deaths in one year; the deaths being mostly from two diseases, dysentery and its common sequel, tropical abscess of the liver. Docker's method, with its huge dosage of 60 to 90 grains, is described at some length by Dr Sydney Ringer in his *Handbook of Therapeutics*, 13th ed, 1897, page 442. The Treasury granted Docker £400 in recognition of the system revived by him. He died on November 8th, 1887.