behind AotW

I have been looking into the death of Private William Anderson Laws, Co. F, 23rd North Carolina Infantry in the Medical and Surgical History of the War of the Rebellion (MSHWR). Private Laws was wounded at Fox’s Gap on 14 September 1862, treated in Middletown, and then at an Army hospital in Frederick. He died there, apparently from a reaction to chloroform during prep for surgery on 28 October.

A few pages later in the MSHWR, though, I found this fascinating plate of surgical instruments used in resection. I had to share.

Does anyone know what the massive, complicated instrument on the left was for? Truly frightening!