100 OBSERVATIONS ON LIGATURE OF ARTERIES 



to this view, the oil remains turbid for a very long time, the finer particles of 

 water being extremely slow in precipitating, and if, after the lapse of weeks, 

 a piece of dry unprepared gut is suspended in it, the thread is soon rendered 

 soft and opaque by the very liquid in which gut which has been longer immersed 

 is growing constantly firmer and more transparent. It is necessary that the 

 gut be kept suspended so as not to touch the bottom of the vessel, for any parts 

 dipping into the layer of precipitated water would fail to undergo the change 

 desired. The vessel containing the emulsion should be left undisturbed, for 

 if the water is shaken up with the oil the process is retarded. An elevated 

 temperature of about ioo° Fahr. seems for a while to promote the change, but 

 ultimately leaves the gut in an unsatisfactory state compared with that obtained 

 at an ordinary temperature. And conversely some portions of gut which I have 

 prepared lately (February 1870) in a room without a fire, in cold weather, at 

 a temperature of about 46°, were in one week already in a trustworthy con- 

 dition for surgical purposes. Hence the gut should be prepared in as cool 

 a place as possible. The longer it is kept in the emulsion, the better the gut 

 becomes. I once feared that it might in time grow too rigid for convenience, and 

 possibly brittle also ; but experience shows that this is not the case. When 

 removed from the emulsion it soon dries in the air, but retains a considerable 

 portion of its carbolic acid for several hours, so that no apprehension need be 

 entertained of loss of its antiseptic property from exposure during the perform- 

 ance of an operation. In course of time it loses all the carbolic acid also, but 

 retains permanently its altered molecular condition. If thus kept dry, as may 

 prove the most convenient for the manufacturer on a large scale, it must be 

 steeped thoroughly in some antiseptic lotion before it is used. And for the 

 surgeon the most convenient way will probably be to keep it always in the 

 antiseptic emulsion, so as to be ready for use whenever it is required. 



For tying an arterial trunk in its continuity, catgut at least as thick as 

 common 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. Several yards of 

 fine gut may be carried in the pocket-case, on a winder contained in a little 

 oil-tight silver capsule which I have had constructed for the purpose, as an 

 appendage to a caustic-holder. 



