Croker (1857); p.534 ff. Croker includes the full text of Sanson's "Memorandum of Observations on the Execution of Criminals by Beheading.".
Croker (1857). See p. 556: "It was in exhibiting one of these heads to the people that the younger Sanson [Gabriel] fell off the scaffold and was killed." See alsop.570: "He [Charles-Henri] had two sons, but one of these was killed on August 27, 1792, by falling from the scaffold...."