INTRODUCTION. Y 



health or prevents recovery from a pre-existing disease. This 

 class of operations includes the opening of abscesses, the extii'pa- 

 tion of gangrenous parts, or of necrosed or carious bone ; or again, 

 for the modification of the nature of a traumatic lesion, in order to 

 stimulate cicatrization, as in the opening of a fistulous tract, or 

 the resection of an ulcerated surface; or when the economy is to 

 be relieved from the presence of a foreign body, or the abnormal 

 product of a natural function, as in cases of oesophagotomy, or 

 of calcuh of the bladder, or of the saUvary ducts. Operations have 

 also their prophylactic uses, especially in the various forms of in- 

 oculation and vaccination as anticipatory and preventive of infec- 

 tious diseases. They find their further obvious indications, again, 

 in remedying physical lesions when applied to fractures, dislo- 

 cations, deformities, and the endless Hst of accidental injuries, 

 wounds and hurts of every kind and degree. And, finally, they 

 have their justifiable use in mutilating the larger domestic animals, 

 designed for purposes of labor as beasts of burden or draught, in 

 improving their adaptability by castration or spaying, or as prop- 

 erly termed, "altering." 



Thus the general purpose of an operation is to paUiate, cure 

 or assist in the recovery of surgical diseases ; to prevent diseases, 

 and especially such as are known to be contagious; and so to 

 modify the condition of the domesticated animals as to enhance 

 their usefulness and value to their human owners. 



In medical nomenclature, operations are variously designated 

 according to the methods and characteristic manipulations attend- 

 ing their performance, and the objects which they are designed 

 to accomplish. Thus: 



(a) It is a light operation when superficial tissues or those of 

 secondary importance are involved, like that of venesection, or the 

 simple pimcture of a vein. On the other hand, it becomes serious 

 when it is performed upon important organs, or involves extensive 

 and compHcated structures, as that for the reduction of strangu- 

 lated hernia; the removal of the lateral cartilage of the foot in a 

 case of quittor; the operation for chronic champignon, etc., etc. 



(b) Operations are also dri/ or bloodless when accompanied by 

 little or no hemorrhage ; and sanguinary or bloody when, on the 

 contrary, much hemorrhage attends any of their various steps. 



(c) Again, they are simjile or complicated according to the 

 extent and multiplicity of the tissues or regions forming their 



