He resided at Coxbench Hall, Derbyshire and was a member of the Derby Philosophical Society where he received encouragement from Erasmus Darwin.
With Henry Redhead Yorke, he wrote the French Revolution-inspired "Derby Address".
They broke with it, however, in 1793, over a resolution of the Club in favour of a French invasion of Great Britain.
[5] Johnson was author of History of the Progress and Present State of Animal Chemistry published in three volumes in 1803.
[7] From the point of view of clinical chemistry, somewhat neglected at the end of the 18th century, Rosenfeld regards Johnson's work as attempting "to present the subject on a larger scale and with a more connected and systematic arrangement.