Industrial chemist. Born in Ochiltree (East Ayrshire). Having followed an apprenticeship in weaving, Tennant went on to set up a bleachfield near Paisley. Tennant became the foremost industrial chemists of his time, producing dyes and bleach for an expanding textile industry. He made a fortune from a bleaching powder which he patented in 1799. For the first time, bleach was easily transportable to the bleachfields around the country. His factory at St. Rollox in North Glasgow became the largest chemical plant in the world at that time.