=Catgut in the Ligature of Arteries.=—In a communication to the _Lancet_, Professor Lister, after giving numerous pathological details, refers to the practical importance of catgut as a ligature. He states that by applying a ligature of animal tissue antiseptically upon an artery, whether tightly or gently, we virtually surround it with a ring of living tissue and strengthen the vessel where we obstruct it. This antiseptic animal ligature consists of catgut steeped in carbolic acid and oil. And with such a ligature Professor Lister says he should now “without hesitation undertake ligature of the innominate, believing it to be a very safe proceeding.” He thus expresses himself as to the necessary qualities of the ligature:—“The method which I have found to answer best is to keep the gut steeped in a solution of carbolic acid in five parts of olive oil, with a very small quantity of water diffused through it.” A larger proportion of the acid would impair the tenacity of the thread. If a mere oily solution is employed, the gut remains rigid, the oil not entering at all into its substance. But a very small quantity of water, such as the acid enables the oil to dissolve, renders the gut supple without making it materially weaker or thicker. And, curiously enough, the presence of this small amount of water in the oily solution gradually brings about a change in the gut, indicated by a deep brown colour; after which it may be placed in a watery solution for a long time without swelling, as a portion prepared in a simple oily solution does. This is a great convenience; for an oily solution is unpleasant to work with during an operation, and exposure to the air soon renders gut suppled with water rigid from drying. But when it has been treated in the way above recommended, it may be transferred to a watery solution at the commencement of an operation, and so kept supple without having its strength or thickness altered. “For tying an arterial trunk in its continuity, catgut as thick when dry as ordinary purse-silk will be found best. But for ordinary wounds, where, if one ligature happens to break, another can be easily applied, much finer kinds may be employed, and are convenient from their smaller bulk.” (See _Lancet_, April 3.) =The Advantages of Tracheotomy.=—Mr. T. R. Jessop corroborates the views expressed in our last Number by Mr. A. E. Durham. He gives some very remarkable cases, showing the great usefulness of the operation. Indeed, one case was a veritable resuscitation of life. (Ibid.) =Arsenic a Cause of Shingles.=—The very important problem as to whether arsenic, when continuously administered, is productive of shingles, is again discussed by Mr. Hutchinson. Mr. Hutchinson does not assert the fact to be more than a coincidence, but he relates several very interesting cases in which the prolonged use of arsenic was followed by shingles. (See _Medical Times_, April 17.)