INTRODUCTION 19 



mucous membrane, but generally the former. The hairy skin 

 of animals is an excellent harbor for microbes. It affords 

 countless ruffles and recesses for the accumulation of dirt 

 and is constantly contaminated by exposure to filth. Cultural 

 experiments show that the surface, the recesses and the 

 deepest parts of the follicles are fairly teeming with microbes, 

 and that even the underlying layers may contain them ; and 

 clinical observations as well as the bacteriological investiga- 

 tions indicate clearly that no perfunctory effort is sufficient 

 to entirely dispatch them. The skin of animals, like the hands 

 of the surgeon, is never aseptic no matter how thoroughly 

 it has been cleansed, but despite this apparently hopeless 

 situation experience shows that by thorough disinfection and 

 proper handling a safe state of cleanliness can be produced 

 and maintained in the skin of animals even better than in that 

 of human beings. In fact, if the skin of animals around a 

 wound or around the seat of a proposed incision is properly 

 managed, very few infections will be traced to this source. 

 Skin disinfection must either be thorough or else omitted 

 entirely, as perfunctory lavage tends more to provoke mi' 

 crobian activity than to destroy it. The following steps are 

 recommended when it is desired to take advantage of all 

 available precautions : 



First Step — A Soap and Hot Water Lavage. — The part to 

 be operated upon is well lathered with suds, rubbed briskly 

 for some moments with the finger tips and then rinsed off 

 with pure water. This not only cleanses the field of dirt 

 but also softens the hair for shaving. Around this washed 

 area the hairs are moistened to allay dust and prevent loose 

 hairs from flying about as the patient struggles. The amount 

 of surface. to be thus moistened will depend upon the general 

 cleanliness of the patient, the condition of the coat and the 

 location of the wound. In the spring when the hairs are 

 shedding fast, in dusty, ungroomed patients, and in operations 

 located where dust and hairs will readily fall into the wound, 

 this precaution is no trivial matter. For example, while oper- 

 ating upon a long-haired yearling colt for inguinal hernia 

 during the shedding season a single struggle and a draft of 

 air in the right direction often sends a veritable cloud of 

 hairs over the exposed tissues. Such harmful incidents are 

 guarded against in this preparatory cleansing of the field by 

 moistening the surroundings. 



Second Step — Clipping and Shaving. — The clipping, so 

 far as the working Qf the clipper is concerned, is done more 

 easily when the hairs are dry, but to prevent raising unneces- 



