2l6 MANUAL OF BACTERIOLOGY. 



covered with a layer of cotton on which the catgut rests. 

 The beaker is heated with a Bunsen burner over a sand- 

 bath. The top of the beaker is covered with a piece of 

 cardboard. Through a hole in the center of the cardboard 

 a thermometer passes. Heat is now applied to the sand- 

 bath, and the temperature of the catgut slowly raised to 

 80 C. In this manner all moisture is driven out of the 

 catgut. This degree of heat is maintained for one hour. 

 Cumol 1 at a temperature of 100 C. is now added to the 

 beaker, completely covering the catgut. The beaker should 

 be covered with copper-wire netting to prevent ignition of 

 the cumol, which is very inflammable. The temperature is 

 then increased to 165 C., and kept at this point for one 

 hour. The fluid is now poured off, and the catgut allowed 

 to dry in the beaker on the sand-bath at a temperature of 

 1 00 C. for two hours. It is then transferred to sterile jars 

 or test-tubes until needed, or it may be preserved in sterile 

 alcohol. 



Formaldehyde catgut. 2 Three-quarter-inch glass spools 

 are notched on each flange. The catgut is wound upon the 

 spool tightly in one layer, and evenly, the ends passing over 

 the flange of the spool in the notch; the longer end, after 

 passing through the notch, goes through the barrel of the 

 spool and is securely tied to the shorter end which has 

 passed over the other notched flange. By thus winding the 

 gut there will be enough for one or two ligatures or sutures 

 of good length. Gut prepared by this process tends to 

 contract forcibly, and on account of this strain must be 

 held securely or it will shrink and be useless. The object 

 of winding in a single layer, evenly, is to prevent over- 

 lapping or crossing of one strand over another. If in 



1 Cumol is a fluid hydrocarbon, with a boiling point somewhat above 

 165 C. It dissolves the fat in catgut. After boiling it has a brown 

 color. 



2 Frederick, American Journal Obstetrics, Vol. 89, 1899. 



