132 ELEMENTAEY OPEEATIONS. 



The skin should be well stretched by various movements of 

 the hand, or of the operator, or his assistants, and held 

 tense and smooth, unless it is already sufficiently expanded 

 by the effect of the existing lesion underneath it. Then the 

 operator, holding the iastrument in the first or third position, 

 carries the iastrument, with the edges and the point turned down- 

 ward, to the spot on the surface to be divided, and penetrating 

 through the sMn to the depth desired, completes the incision to 

 its proper length. 



This mode of incising the skin answers for the majority of 

 cases, but there are others when the skin has to be divided care- 

 fully and by layers. Incisions are then made with the convex 

 bistoury, held in either position with its edge downward, carried 

 perpendicularly over the skin and often by repeated hght strokes. 



These two procedures answer when the part to be operated 

 upon offers a certain sohdity. Otherwise the incision can be 

 made in a third manner, viz.: by taking hold of a fold of the skin, 

 held at one end by an assistant, at the other by the operator, and 

 completing it by a transverse section through the fold, made 

 from the apex to the base. The objection to this mode of dividing 

 is that the incision can never be thoroughly Umited. 



2d. Incisions from within outwards. — In contrast vnth those' 

 already considered, these incisions are made from the deep parts 

 toward the superficial, and through the thickness of the skin. 



The Straight Bistoury is here the preferable instrument, either 

 alone or assisted by a guide or conductor, which may be the grooved 

 probe, the director, or the finger of the surgeon. Either with 

 or without, these incisions can be executed in various ways. 



Without the Director. — With the bistoury held as a writing 

 pen, with the blade turned upward, first the point of the instru- 

 ment, and then the entire blade is thrust perpendicularly through 

 the tissues ; then lowering the handle of the instrument until it 

 forms with the skin an angle of forty-five degrees, the iastru- 

 ment is moved in an oblique direction in such a way as to stretch 

 and divide the sMn, until at the end of the incision the bistoury is 

 brought back to a perpendicular direction to complete the incis- 

 ion in a neat manner. This incision can be made toward or from 

 the operator, according to the case. It will facilitate the action 

 of the instrument if the skin back of the hand that holds it is 

 stretched with the free hand of the operator. 



