The investigations of Royle and Hunter, Leriche, Adson, Brown and Rowntree, and others have shown that excision of the upper dorsal or the lower lumbar sympathetic ganglions will bring about vasomotor paralysis of the corresponding extremity, a cessation of perspiration, and the relief of a number of obscure trophic and painful conditions. Such an operation is extremely satisfactory in cases in which the poor circulation is due to overactivity of the vasomotor nerves rather than to arterial obliteration, and also in bringing about the relief of pain when it is referred over the involuntary nervous system. But it is often difficult to make sure of these two important premises in advance and one therefore hesitates to subject a patient in whom the diagnosis is questionable to such a radical operation. In the past, Brown's1intravenous protein shock has been of great service in determining whether a given patient will