Throughout the 19^thcentury, many punishments were applied to prisoners if they misbehaved, the punishment varying by the severity of their actions. The cat-o’-nine-tails was one of  such punishment. It earned its name because when the cat-o’-nine-tails was applied, it

left wounds resembling cat scratches on the backs of convicts. 

The scars were lifelong scars that served to mark social disgrace. Hopper writes about three people who were given this as a punishment. The first was William Porter who was released from Sing Sing on the 12^thof April in 1848 saying “the cat was applied to him in several instances.”

The next one Hopper mentions about receiving the punishment of the “cat” was Hugh Quin. Hopper describes Quin’s punishment in full detail, which seems to be the worst punishment of the cat-o’-nine-tail in this diary. Isaac says “After his return to Sing Sing the second time was floged with the cat six times in five months, with from 25 or 30 Blows each time. On occasion, he received 16 blows for catching a fly in his cell on the Sabbath. He was floged seventy times in eleven years. (The highest offence for which he was punished was talking except in one instance when he resisted the keeper.)”

The last person Hopper talked about getting punished by the cat was a man named Ruben Gray. He was a prisoner at Auburn for three years, and during his time there the club law hasn’t been substituted. The club law was how the prisoners were punished during the 19^thcentury. According to historians, the cat-o’-nine-tails was a dreaded punishment that could rip and tear the skin from the back of the victim, leaving scars for the rest of their lives. 

Sources: 

Welch, Michael. “Suffering and Science.” In Escape of Prison, 167-194. University of California Press, 2015.