82 



SURGICAL DIAGNOSIS. 



growths, prominent swellings and changes of direction in the 

 bony levers, belong to the same category, and if these are not suf- 

 ficiently distinct or conspicuous, and seem likely to escape the 

 visual observation of the surgeon, a careful measurement may de- 

 cide the point. The eye must also discern the changes occurring 

 in the various visible membranes, as for example, the heightened 

 redness of a congested membrane, and the paleness of an anaemic 

 subject. 



Again, if there is abnormal motion in a part, as in fractures 

 and dislocations, it is to the eye that the disclosure is first made. 

 This application and study of the use of his eye will be very 

 serviceable to the surgeon in the examination of the external sur- 

 face of the body, but when examinations ^fvithin the organism, or 

 within its cavity, become necessary, however strong a hght he 

 may have at his disposal, he will be compelled to have recourse 

 for assistance to the speculum, to hold the parts open. 

 There are many forms of this instrument. 



The speculum oris, for the mouth, has very numerous shapes, 

 some of them very simple, as in Figures 70 and 71, and some com- 



FlGS. 70 & 71.— Simple Speculum Oris. 



Fig. 72.— Brogniez Speculum Oris. 



phcated, as in Tig. 72, the speculum of Brogniez. Green's spec- 

 ulum is an American invention, simple, safe, comfortable to the 

 patient, and of easy manij)ulation (Fig. 73). Grange's mouth 

 speculum is rather clumsy and heavj' (Fig. 74). These instruments 

 are generally employed for solipeds. Placed between the jaws, 

 they open the mouth forcibly, and keep it so as long as they con- 

 tiaue in place. 



Sometimes, however, the mouths of these animals, as well as 

 those of ruminants, can be held open without them, by putting 



