88 SURGICAL DIAGNOSIS. 



(c) Hearing. — The indications obtaiaed through the media 

 of the sight and the touch may be usefully supplemented, and are 

 often completed by those which address the sense of hearing- 

 The gurgling sound in Hquid or gaseous tumors, the peculiar 

 bruit in aneurisms, caused by the current of the blood; the con- 

 tact of a stone in the bladder when touched by the exploring 

 catheter; the peculiar glou-gloxt of the entrance of air into a vein; 

 the characteristic crepitation of fractures, and the whistling of a 

 roaring horse — these, and other signs, convey their information 

 with unmistakable distinctness to the auricular sense. 



{d) Smell. — The exercise of the olfactory sense in the formation 

 of a surgical diagnosis is more limited than those just con- 

 sidered, and yet there are conditions in which it may be of great 

 importance. 



The odor, sul generis, of gangrene and of necrosis are 

 promptly detected, and at once recognized, and the existence of 

 other pathological conditions, as of urinary or stercoral fistulous 

 tracts, and certain afi'ections of the feet, are betrayed by the 

 pungent and aggressive appeal to the olfactory organs. 



(e) Taste. — As free from anything Uke fastidiousness in 

 respect to offensive contacts and surroundings, as the sm-geon 

 must unavoidably become, he draws a line ; he insists upon a 

 strict monopoly of his gustatory sense for his own internal uses, 

 and only investigates the domestic animals in an ahmentary way, 

 when entirely healthy individuals are reduced to 2i, post-mortem 

 condition by the butcher, and served in the form of beef, mutton 

 and pork, properly cooked. But if the surgeon should desire 

 much valuable aid from the exercise of the physical senses in form- 

 ing his diagnosis, he will commit a serious error if he allows 

 himself to be entirely and exclusively guided by them. Strictly 

 speaking, a direct diagnosis may sometimes be arrived at by a care- 

 ful collation of the results of his researches, but he will often, 

 also, be obhged to modify or go beyond these conclusions, and 

 make an indirect diagnosis besides. 



There are two ways of making a positive surgical diagnosis 

 one which may be called the du-ect, or diagnosis by confirmatioii 

 another known as indu'ect, or by exclusion. The former is by 

 ulterior investigations, confirming a previous diagnosis made upon 

 the basis of a single and prominent symptom ; the latter by the 

 elimination of aU diseases, which, though they may have some 



