eating a partial vacuum, thereby drawing blood from the patient. To create many incisions at once, the spring-loaded blades of the scarifactor are used.
Given the serious nature of battlefield wounds and the crude level of treatment, did anyone actually survive the surgeon's ministrations? Perhaps surprisingly, yes! For example, for 146 major operations (shoulder joints, thighs, legs, arms) performed on soldiers in June and July 1815 in British general hospitals in Brussels, the survival rate was 78%. This may not be acceptable today but not bad for the nineteenth century!
It turns out that battlefield wounds were not the primary worry of soldiers on campaign: disease was. Far more soldiers died from the harsh, unhygienic conditions in camp than from actual battle. During the Peninsular War from 1812-14 the four major causes of mortality among British soldiers were as follows:
All things considered, we are much better off with twenty-first century medicine!
(statistics cited from Wellington's Doctors by Dr. Martin Howard)