PREPARATION OF INSTRUMENTS, ETC. 215 



diately after use instruments should be thoroughly scrubbed 

 with a brush and washed with soap and hot water and 

 boiled, before being replaced in the instrument case. 



The practice of passing an instrument through a flame 

 a few times cannot be relied on to destroy the bacteria that 

 may be present. 



Aspirating syringes, needles, trocars, drainage tubes and 

 glass nozzles are best sterilized by boiling for ten minutes. 

 If syringes have leather washers (which should be avoided) 

 they may be cleansed with hot water and soap, rinsed with 

 alcohol, filled and refilled with boiling water ten or more 

 successive times, and placed in a 1-40 carbolic acid solution. 



Instrument trays, ligature dishes, basins for sponges, etc., 

 are to be sterilized by boiling for ten minutes, and protected 

 from dust with sterile towels. 



Catgut is made from the intestines of sheep, and sheep are 

 subject to anthrax infection, while tetanus bacilli may occur 

 in the intestine. Therefore, catgut must be sterilized by 

 some method that will kill the spores of these organisms if 

 present (see Bacilli of anthrax and tetanus, Part IV.). 

 There are many methods devised for the preparation of 

 sterile catgut that have as a basis an incorporation within 

 the catgut of some antiseptic. They are open to the objec- 

 tion that any antiseptic introduced into the tissues acts as an 

 irritant, aside from the fact that organisms may be liberated 

 from partially absorbed catgut. This is seen in cases of 

 late suppuration ten to fifteen days after an operation. 



Catgut comes in sizes from double zero up to No. 8. The 

 sizes mostly used are o to 4. Catgut when ready for use 

 should be smooth, soft, pliable, and very strong ; wiry catgut 

 is apt to cut through tissues. 



Cumol method. 1 The catgut is rolled on glass spools, and 

 these put in a glass beaker. The bottom of the beaker is 



1 Clark and Miller, Bulletin Johns Hopkins Hospital, Vol. XL, Sep- 

 tember, 1900. 



