CAT′GUT. The prepared and twisted intestines of animals. Prep. The guts, taken whilst warm from the animal, are thoroughly cleaned, freed from adherent fat, and well rinsed in pure water. They are next soaked for about 2 days in water, after which they are laid on a table and scraped with a copper plate, having a semicircular notch, beginning the operation at the smaller end. In this way the mucous and peritoneal membranes are removed. The guts are then put into fresh water, and soaked until the next day, when they are again scraped, the larger ends cut off, and after well washing, again steeped for a night in fresh water, and then for 2 or 3 hours in a weak lye of pearlash or potash (2 oz. to the gall.) They are lastly washed in clean water, and passed through a polished hole in a piece of brass to smooth and equalise their surface; after which they are twisted, and sorted, according to the purposes for which they are intended. For many purposes the prepared gut is dyed or sulphured, and rubbed with olive oil. It improves by age. Red or black ink, or any of the simple dyes or stains, are used to colour it.
Uses, &c. Catgut is employed in several of the arts. The strings of harps, violins, &c., are formed of this material. Whipcord is made from catgut, which is sewed together while soft with the filandre or scrapings, after which it is put into a frame and twisted. Bowstrings for hatmakers are made out of the largest intestines, 4 to 12 of which are twisted together, until the cord is extended to 15 to 25 feet in length. It is then rubbed perfectly smooth and free from knots, half dried, sulphured twice, again stretched and sulphured, and lastly dried in a state of tension. Clock-makers’ cords are made of the smallest intestines in a similar manner.
The best fine catgut is made at Venice or Rome, from the intestines of thin, sinewy sheep. That made in England is formed from the fat sheep killed for the shamble, and is, hence, inferior. Coarse catgut, for turning lathes, &c., is made from the intestines of horses, cut into 4 or 5 strips, by forcing a ball furnished with projecting knives placed cross-wise along them. These strips are next twisted, dried, and rubbed smooth with fish skin. Gutta percha and vulcanised india rubber are now applied to many of the purposes formerly exclusively occupied by catgut.
CATHAR′TICS. See Purgatives.
CATHAR′TIN. The purgative principle of senna, first noticed by Lassaigne and Fenuelle. A strong aqueous infusion of senna leaves is evaporated to the consistence of a syrup, out of contact with the air; this fluid extract is then digested in alcohol or rectified spirit, and
the tincture, after filtration, is evaporated to dryness by a gentle heat.
Prop., &c. A reddish-coloured, uncrystallisable mass; having a peculiar odour and a bitter, nauseous taste; freely soluble in both water and alcohol, and strongly cathartic. Two or three grs. cause nausea, griping, and purging. It has been proposed to employ it, combined with aromatics, as a cathartic.
CATH′ETERS. Small tubes introduced into the bladder for the purpose of drawing off its contents. They may be regarded as hollow bougies.
Prep. 1. A piece of smooth catgut, or steel wire, bent to the proper shape, is coated with melted wax. When cold it is dipped repeatedly into an ethereal solution of india rubber, until a sufficient thickness is obtained, after which it is dried by a gentle heat, and then boiled in water to melt out the wax, and to allow the catgut to be withdrawn. A solution of india rubber in bisulphide of carbon is now generally employed instead of an ethereal solution.
2. From slips of india rubber, as directed under Bougies.