To one who has carefully studied the sequence of events following the customary drainage of chronic brain abscesses, the conclusion is inevitable that many patients so afflicted succumb from the effects of the treatment rather than from the abscess itself. The fact that abscesses in the soft parts are successfully treated by wide drainage, or by drainage and irrigation, is no reason why the same treatment will produce the same results in abscesses of the brain. It is only necessary to compare the structural differences between the brain and the soft parts to understand why drainage affecting the brain is an entirely different problem. The brain being a very delicate and well protected structure and, therefore, unaccustomed to trauma of any kind reacts slowly, weakly and less effectually to the insults of trauma, which drainage must necessarily induce. Proof of this statement is to be found in extirpations of tumors,