in addition to his domestic pursuits, bell also served as a military surgeon, making elaborate recordings of neurological injuries at the royal hospital haslar and famously documenting his experiences at waterloo in 1815. for three consecutive days and nights, he operated on french soldiers in the gens d'armerie hospital. the condition of the french soldiers was quite poor, and thus many of his patients died shortly after he operated on them. dr. robert knox, who was one of bell's surgical assistants at brussels, was quite critical of bell's surgical skills. he commented very negatively on bell's surgical abilities; (the mortality rate of amputations carried out by bell ran at about 90%).