It is several years ago, in May, 1889, that I first drew the attention of the profession to the value and importance of exploring the brain with a needle through small apertures made in the skull. This method was proposed to take the place of trephining, i.e. removing a ring or bone, before exploring the subdural spaces and the brain. The simplicity of the procedure and its safety recommended it as an easy means within the reach of a greater number than the other more serious and comparatively complicated operation of the trepan. By its ready employment it was expected that many lesions, specially abscesses, cysts and hard tumors, could be earlier diagnosed and located with certainty after exploring by this means the region suspected from the distant symptoms.
To determine first the possible dangers from hemorrhage I conducted a number of experiments on dogs. The manner of proceeding was