One of the first campaigners on the matter was the eminent physician, Benjamin Ward Richardson, who spent many years of his later working life developing more humane methods of slaughter as a result of attempting to discover and adapt substances capable of producing general or local anaesthesia to relieve pain in people.
32.
In 1918 the American neurosurgeon Walter Dandy introduced the technique of ventriculography whereby images of the ventricular system within the brain were obtained by injection of filtered air directly into one or both lateral ventricles of the brain via one or more small trephine holes drilled in the skull under local anaesthesia.
33.
Morphine in particular was used much more widely after the invention of the hypodermic syringe, and the practise of local anaesthesia by infiltration was another step forward in medicine resulting from the hypodermic needle, discovered at around the same time that it was determined that cocaine produced useful numbing of the mucous membranes and eye.
