CATGUT. (FR., Cordc de boyau ; GER., Katzendarm, Darmsaite.) The term " catgut " is applied to membranous substances prepared from animal intestines, gene rally those of sheep, more rarely those of horse, ass, and mule, but never those of the eat. Two methods of preparation are used, according to whether it is desired to produce twisted c,ord, or flat strips of membrane. In the former case, the first stage in the operation is the thorough cleansing of the intestines from the adherent feculent and fatty matters, after which the small ends are tied together, and placed over the edge of a tub, while their major portion is left for two days to soak in water, which is constantly changed. In this way, the peritoneal and mucous membraues are loosened. The bundle of intestines is then laid on a sloping board overhanging the tub, and their surface is scraped by a square steel edge, the external membrane being removed in breadths of about half the circumference of the intestine. This membrane, which the French call filandre, and which is employed for the cords of battledores and rackets, and also as a thread for sewing the ends of intestines together, cetnnot be removed by beginning at the large end. The scraped intes tines are then steeped for one night in clean water, and next day are again scraped with a rounded edge ; this process is called " curing." The large enda are now cut off, salted, and stored in covered tubs for sale to the sausage-makers. The small parts are again steeped for one night in fresh water, and next day are treated with an alkaline mixture, consisting of 4 oz. potash, 4 oz. carbonate potash, and 3 to 4 gall. water. After this, they are distributed to a number of women, each having two basins of the alkaline solution before her, and are drawn through a perforated brass thimble, pressed against the edge, for the purpose of rendering them smooth and equal. They are thus passed from one to the other of the two basins several times, and are then assorted according to their sizes.
In order to produce a cord—known as " whipcord "—from these intestines, they are sown together by means of the filandre before mentioned, the joints being cut aslant to make them smoother and stronger. A number of these cords are then put into wooden frames, whose two uprights are fur
nished with a series of holes, containing pegs for securing the ends of the cords, and for passing the lengths round. The spinner attaches the end of one of the cords to the hook of a little whirling apparatus, similar to but smaller than the whirl of the rope-maker, which he causes to rotate rapidly by means of a handle. This puts a twist into the cord, and somewhat diminishes its length ; the twist is retained by pegging the cord on to the frame. The others are then treated in this way, and when all are completed, the frames are piled up horizontally in a small close chamber lined with thin sheet lead, whero they are subjected to the fumes of burning sulphur. This process is called " bleaching," but that is a misnomer, as the alkaline solution has already whitened the gut ; the real object of the sulphuring is to prevent the putrefaction of any animal matter which may still be accidentally adhering. The cord may now be dyed black with common ink, or red with red ink, or green, taking the dye readily. The twist being eompleted, the eords are nicely smoothed, and then placed for an hour or so in a hot room-82°-93°(180°-200° F.)—which fixes and consolidates them. Lastly, they are cut off the frames and twisted into cords for sale.
Tbe so-called " hatters' cords," for bowstrings, used in one of the stages of hat-making, are made of the longest and largest sheep guts, which, after being properly smoothed and cleaned with the alkaline solution, are twisted in lengths, 4, 6, 8, 10, or 12 together, according to the intended size of the cord, which is usually about 12 ft. long. This eord must be free from lumps and knots ; when half dry, it is sulphured twice, a,nd after each operation, is well stretched, twisted, and smoothed, and finally dried in ft state of tension.