likely--mainly by increased intra-tracheal air-pressure. There must, however, I think, coexist some deficiency or weakness of the cartilaginous or other tissue, either congenital or acquired. When the dilatation is retro-tracheal only, the symptoms are very obscure, and diagnosis during life is at best uncertain. In one such case under my care, confirmed (death having occurred from another cause) by post-mortem examination, there was some dysphagia and slight alteration of the voice. In all other cases the characteristic and unmistakable sign of the disease is the peculiar intermittent, or, at all events variable, aërial cervical tumor. It increases and diminishes with forcible expiration and inspiration, and attains its largest size during violent coughing, hawking, blowing of the nose, or other expiratory effort. Occasionally the voice is considerably affected. The tumor, especially by the manner in which it can be made to temporarily disappear and reappear, can usually be easily differentiated from subcutaneous emphysema and goitre, the only two conditions with which it might be confounded. In the fistular variety the opening into the trachea can sometimes be seen by means of tracheoscopy. Aside from the deformity which the tumor may cause, it sometimes induces laryngeal spasm and dyspnoea; otherwise it is of no gravity. As to TREATMENT, methodical and continued compression by applications of astringent collodion or by mechanical means is the only palliative measure applicable; when suffocatory attacks call for it, tracheotomy must be performed. {145} TRACHEOTOMY. BY GEORGE M. LEFFERTS, A.M., M.D. The operation of tracheotomy, or the artificial opening of the air-passage--using the term in its modern acceptation as including all of the five incisions that are both anatomically and surgically possible, either singly or in combination, between the lower border of the thyroid cartilage and the upper edge of the sternum (incisura jugularis sterni), and reserving the term laryngotomy to denote the division of the thyroid cartilage alone--fulfils two important and usually urgent indications: First, in allowing the respiratory current free access to the lungs in cases where the laryngeal obstruction is of such a sudden or of so progressive a character as to either immediately or remotely threaten the life of the patient; and, secondly, in affording a ready means of direct access to those portions of the air-tract which lie below the level of the glottis, and thus permit not only of the direct extraction of such foreign bodies as may accidentally have found their way within the air-passage, but of neoplasms here located and of occluding diphtheritic membranes. Catheterization and aspiration of the trachea are likewise both rendered not only possible, but easy of execution. Both general indications mentioned often coexist, and are met by the operation in a large class of cases; the first alone plays its important life-saving rôle in many.