Most investigators dealing with problems of the pathogenesis and pathophysiology of convulsive disorders have been concerned with discovering an animal preparation which, with reasonable fidelity, can mimic the chronic, recurrent, paroxysmal disturbance of human epilepsy. The discovery of the aluminum hydroxide technique by the Kopeloff's1 was a fundamental advance in this regard. Local injection or application of alumina (aluminum oxide) cream will produce a chronically discharging lesion with fair regularity. However establishment of such a focus requires from six weeks to three months to develop. Once established, it may persist for at least two to three years. Some years before this, Speranskii,2 and more recently, in a better controlled fashion, Keith and Bickford,3 had experimented with local cortical freezing. This method produced a local discharging lesion in a matter of hours after application but had the disadvantage of disappearing after 7 to 10 days. Both the alumina