190 VETEEINAKY MEDICINE AND SURGERY. 



Sulphate of zinc gr. x. 



Water ^i. 



or of: 



Tincture of iodine gr. v. 



Iodide of potassium 3 i. 



Water 1 vi. 



and the orifice of puncture kept open until the cavity of the cyst has be- 

 come obliterated. Another plan is to excite the suppurative action in it 

 after it has been punctured, by injecting a stimulating mixture: 



Solution of acetate of ammonium § i. 



Olive oil § ij. 



or by inserting a seton through its centre. It is useless to puncture and 

 allow the wound to close immediately, for the walls of the sac have ac- 

 quired secreting properties, and continue to pour out the serosity, which 

 will speedily fill the cavity of the cyst. It is therefore necessary to keep 

 the puncture open until the walls of the sac have become adherent to 

 each other, and its cavity destroyed. 



"When the cyst has become consolidated by the causes already given, it 

 will often be found that a little suppuration occurs in the centre of the 

 tumor; but it is never very extensive, and the suppurated spot is sur- 

 rounded by a thick wall of condensed fibrous tissue of a grayish appear- 

 ance. 



There are two ways of removing the tumor when in this condition — 

 by excision, and by sloughing it with caustics; the latter being consid- 

 ered the best, provided it is carefully done. Puncture the tumor in two 

 or three places, and insert into each puncture a very small quantity of 

 finely powdered corrosive sublimate and arsenic, in equal parts, rolled up 

 in a small piece of tissue paper. The effect of this is twofold: — (Is^.) 

 It destroys the vitality of the tissue which it touches; and {2d.) Excites 

 absorption throughout the whole extent of the tumor. The absorption 

 first excited in the living structures in immediate contact with those de- 

 stroyed by the agent, whereby a line of demarcation is formed between 

 the living and dead tissue, becomes general throughout the tumor, and 

 in a few days it will be seen that it has diminished in volume in every 

 direction. After the sloughs caused by the caustics have been removed. 



