The entrance of air into a vein during the operation is a possible accident, especially when it is much enlarged and imbedded in dense tissue, as sometimes occurs in malignant disease of the throat or when large tumors of the parts exist. Should such an unfortunate complication occur, the proper treatment, according to Erichsen, should be compression of the wounded vein with the finger and its immediate ligation if possible; compression of the axillary and femoral arteries and a recumbent position for the patient to favor cerebral circulation; and, lastly, artificial respiration. At the moment of opening the windpipe two conditions may suddenly {159} supervene, both of which need, as may usually be easily done, differentiation from the asphyxia produced by the entrance of blood into the trachea. The first of these is the apnoea which not unfrequently arises in children suffering from urgent dyspnoea the moment that a free opening is made and the air-stream rushes unimpeded into the lungs. The condition lasts but a moment or two, and need excite no alarm. The second is based upon the fact that the operation itself not seldom excites an alarming asphyxia, probably by provoking laryngeal spasm. The introduction of the tube serves to promptly relieve it. Finally, I may refer to those rare but unfortunate and unpreventable cases where the introduction of a tracheotomy-tube after a carefully conducted operation fails to give relief. Such instances are reported by several authors, and depend upon the existence of some unascertained pathological lesion, such as the presence of a stricture of the trachea below the site of the operation, compression of this tube from without or a tumor within, stricture of the primary bronchi, or some similar condition. A careful preliminary examination and study of the case will in the majority of instances do much to fix the indications for the operation and perhaps account for the surgeon's failure.