Born on 6 May 1848 in Lewisham, Kent. Attended Colfe Grammar School, Dartmouth Hill, and from 1865 studied chemistry at the Royal College of Chemistry in London under A. W. Hofmann and Edward Frankland. Assisted Frankland in developing methods for water analysis used by Frankland in a survey of the British drinking water supply. Studied chemistry under Hermann Kolbe in Leipzig from 1867-1870. Worked at the London Institution as professor of chemistry from 1871–1884. Also worked with the City and Guilds of London Institute, first at Finsbury College where he organised classes in technical chemistry, and then as professor of chemistry at the new Central Institution at South Kensington. At both institutions Armstrong pioneered science teaching methodologies and courses in higher technical education for engineers and chemists. The chemistry school was among the first in the country to train chemists for work in factories, and the first to produce what were later called chemical engineers. Married his wife, Frances Louisa, on 30 August 1877. The couple had three daughters and four sons. One of the sons, Edward Frankland Armstrong, became an industrial chemist. From 1886-1896, Armstrong worked with William Palmer Wynne on the chemistry of naphthalene. Their research was of fundamental importance to the manufacture of dyestuffs, when naphthalene came to be used as a starting material for the manufacturing process. The Central College was amalgamated with Imperial College in 1912. Armstrong retired, and became an elder statesman of British science. Armstrong died at his home in Lewisham on 13 July 1937.