io8 ON THE CATGUT LIGATURE 



and by this means, as the people express it, the dirt is scraped out. That which 

 these persons call the dirt is the exquisite and complicated structure of the 

 intestinal mucous membrane. But while the mucous membrane is scraped out 

 from within, there is also scraped off from without, the circular coat of muscular 

 fibres. The result comes to be that the intestine is converted into a compara- 

 tively unsubstantial material, consisting of two parts, or bands, one more slender 

 than the other. When the intestine is stripped from the mesentery by the 

 butcher, the peritoneal covering of the gut shrinks into a narrow strip, and 

 this, with some longitudinal fibres, constitutes the more slender of the two 

 parts to which the intestine is reduced by the process of scraping. The other 

 part is the essential material from which the catgut is prepared, and this is 

 neither more nor less than the submucous cellular coat of the intestine. When 

 I first visited a catgut manufactory I was astonished to find that, after this 

 scraping process, the intestine could be blown up still as a continuous tube, 

 as you see can be done with this specimen, which has been treated in the manner 

 I have described. This translucent membranous tube is a beautiful anatomical 

 preparation of the submucous cellular tissue, though made in so rude a fashion. 

 This coat of the intestine, which in the sheep has such extraordinary toughness, 

 is the material out of which the catgut is prepared. For what the manufacturer 

 terms the ' ones ' — the thicker form of ordinary catgut — all that is done is to 

 twist the entire tube by means of a wheel, like a rope in a rope-walk, up to 

 a considerable degree of tightness, and then allow it to dry. It is afterwards 

 exposed to the fumes of burning sulphur, and for some more special purposes 

 it is bleached by the action of potash. But the essential thing is the twisting 

 and drying. It can be manufactured without sulphur, as well as without potash. 

 Some specimens which I have here were made by means of water only, without 

 the use of any other ingredient. This exceedingly beautiful material, as fine 

 and smooth as a horsehair, is nothing but the animal tissue twisted and dried. 

 For the finer kinds the submucous coat is split up by means of razor blades, more 

 or less numerous, according to the degree of splitting required, connected with 

 a conical piece of wood which is pushed along the tube. 



Such, then, is the material with which we have to deal. The first of the 

 more recent experiments which I performed with reference to it was made with 

 the view of ascertaining, if possible, what part the water played in the ingredi- 

 ents used for the preparation by our old method. If I steep unprepared catgut 

 in a mixture of dry carbolic acid and oil, however long it be so steeped, although 

 it will be of course abundantly aseptic, it remains utterly unfit for the purposes 

 of the surgeon ; a knot upon it would still slip in a wound. But if, instead of 

 using carbolic acid in the crystalline state, we use carbohc acid which has been 



