It was a crime of passion of such disfiguring violence that Victorian London was left scandalised. In November 1865, Felix Deacon, a young lithographer who had fallen for a married woman, Sarah Ann Peacock, was attacked in the street. His assailant was not her husband but another man, a dentist by the name of Wainwright, who was equally smitten with Mrs Peacock and therefore saw Deacon as a rival.

The method he employed to warn him off was as familiar and feared in those times as it is today in modern Britain. Wainwright threw vitriol, a form of sulphuric acid, into Deacon’s face, blinding him. He was jailed for 20 years for his crime.

No longer able to work because he could not see, Deacon, ended up destitute in the St Pancras workhouse, but help was at hand. A volunteer from the Home Teaching Society for the Blind taught him Braille, and a public appeal raised the £50 needed to buy him an adapted knitting machine so he could once again earn his own living.

The headlines in recent years that have accompanied spiralling numbers of acid attacks – up from 261 cases reported to the Metropolitan Police in London in 2015 to 454 in 2017 – tend to treat them as a new kind of threat to public safety. Yet, as the case of Felix Deacon reveals, they have around for a long time. Their characteristics, though, have changed.