76 DISINFECTION OF INSTRUMENTS. 



avoid touching the skin surrounding the point of operation, the table, 

 the straw or any object which has not been disinfected. Even when 

 nothing suspicious has been touched, it is well during operation to 

 rinse the hands from time to time in a disinfectant ; should the 

 hands actually have been soiled, they must immediately be cleansed 

 again. 



Disinfection of Instruments. The handles of modern instruments 

 are generally made of German silver, nickel, or aluminium. They 

 should present no unnecessary ornamentation, depressions, grooves, 

 corrugations, or spots likely to hold dirt. Instruments like scissors, 

 forceps, etc., should be capable of disarticulation for cleansing 

 purposes, and complicated instruments difficult to clean should be 

 discarded. Wherever possible instruments should be in one piece, 

 like the retractors in Figs. 77, 78, and 79 ; for more complicated 

 instruments the French joint, as shown in the lion forceps, Figs. 80 

 and 81, is the best. For sutures, Largu's or Mooij's needles are 

 preferable to others, being simple and readily sterilised. For syringes 

 with pistons one can often substitute a simple glass tube carrying 

 a rubber ball, the piston being then replaced by a column of air. 

 Many methods and materials for rendering instruments aseptic have 

 been recommended. Immersing the instruments for a minute in 

 pure carbolic acid and afterwards rinsing them in a 5 per cent, 

 carbolic solution is advised by many surgeons. Boiling in water 

 is a simple and practical method ; and any detrimental effect on 

 the blades can be prevented by adding one per cent, of sodium 

 carbonate. Where a higher temperature of 250° to 260° F. is required 

 the bath may be of oil or glycerine. The vessel in which this boiling 

 takes place should be provided with a tight lid, so that after boiling 

 the whole may be placed on one side to cool. Immediately before 

 operation the instruments are removed from it, and placed in trays 

 containing an antiseptic solution (3 per cent, carbolic), in which 

 they remain until required for use. Should the operator have 

 finished with an instrument for the moment it should be rinsed in 

 a separate vessel and then returned to the solution, and never allowed 

 to come in contact with the straw or be laid on the animal's body. 

 Trays of glass or porcelain are very useful, though vulcanite is also 

 largely employed, being much less brittle. All vessels of the 

 kind must be subjected to a thorough cleansing before use. As 

 instruments with wooden handles are damaged by boiling, they 

 should be disinfected by cleansing and prolonged immersion in 

 five per cent, carbolic solution. They should not be used in aseptic 

 surgery. 



