PRINCIPLES OF VETERINARY SURGERY 265 



rain-water cistern may contain very harmful micro-organ- 

 isms, and should therefore never be used except for making 

 exceptionally strong antiseptic solutions. 



y. The Surgical Dressings. — These include, wound- 

 packings, bandages, drainage tubes, plastic dressings, the 

 bailing sponge, and often the dry antiseptic. Lister paid a 

 great deal of attention to this item. He covered up the 

 wound with layer after layer of antiseptic fabrics, and then 

 with sheets of impervious material, with the purpose of ex- 

 cluding the microbes of the air, but it has since been shown 

 that rather unnecessary efforts were made in this direction 

 during the first years of antiseptic surgery. The packings 

 placed into the wounds of animals to arrest haemorrhage or 

 to absorb wound secretions are either absorbent cotton, 

 gauze, oakum, lint or waste. These substances may be pur- 

 chased in various forms, — antiseptic or aseptic, — packed in 

 sealed jars or metal packages, but they are too expensive 

 for veterinary operations generally. It is necessary to use 

 the crude product and to make it safe by economical meth- 

 ods. The ordinary absorbent cotton purchased in pound 

 packages is clean, and it can be made quite safe by immer- 

 sing in mercuric chloride or carbolic solutions for some min- 

 utes before inserting it into the wound. Dry, it can not be 

 recommended as absolutely aseptic until it has been passed 

 through some form of disinfection. Waste, oakum and lint 

 must be immersed for some time before they are absolutely 

 safe. 



A very economical and safe wound packing is made from 

 cheese-cloth. It is torn into strips four inches wide and sev- 

 eral yards long, wound up into loose bandages and kept im- 

 mersed continually in a strong solution of mercuric chloride. 

 A large, two-gallon, salt mouth bottle may be kept full of 

 such packing ready for use at all times. The same recom- 

 mendation is made for the protecting bandages, with the 



