728 DISEASES AND ABNORMALITIES. 



and less friction, may be employed to herniae which are not so consider- 

 able in volume, and are covered by fine skin. When the animal has to 

 be thrown and placed on its back, the quantity of acid and amount of 

 friction must also be diminished. Dayot recommends that the application 

 be repeated once or twice in the hour, according to the thickness of the 

 skin ; but it has been found that one application is generally sufficient, 

 fifteen days being allowed to elapse in order to watch the result. If at 

 the end of this time the skin is not destroyed, the application may be re- 

 peated. 



The nitric acid produces a yellow eschar, which, if not dry on the first 

 day, soon becomes soft, unctuous to the touch, and easily destroyed. With 

 the formation of this eschar, there is much swelling, either immediately 

 on the application of the acid, or soon after ; in some cases there is but 

 little if any swelling. The tumefaction is due to the action of the nitric acid 

 on the subcutaneous connective tissue, which is infiltrated, and causes a 

 uniform pressure on the hernied mass ; this leads to the latter being 

 pushed into the abdomen and kept there as if by a truss. The cedema- 

 tous swelling established external to the tumor, is oblong and depressed 

 in the centre, in consequence of the diminished elasticity of the central 

 portion of the escharified skin ; in a few days it is gradually absorbed 

 and becomes more consistent, while the skin in the centre becomes dry 

 and hard, like parchment. Instead of the hernia, there is now only a 

 newly-formed' mass of fibrous tissue, which is gradually lessened in vol- 

 ume, condensed, and partly absorbed, like cicatricial tissue. At the same 

 time the cauterized skin begins to be thrown off at the margin, the pro- 

 cess of separation extending to the centre, where it takes a long time to 

 be completed, because of the remains of the umbilical cord. When com- 

 pletely detached, there is a granulating healthy-looking wound left, which 

 may have some fibrous masses in its middle. This suppurates, dries, be- 

 comes covered with a crust, and is gradually furnished with epithelium. 

 In retracting, the wound contributes largely in closing the hernial open- 

 ing, while the indurated skin which continues for some time to adhere to 

 the abdominal walls, through the medium of the condensed connective 

 tissue, contributes its share. In about a month cicatrization is finished ; 

 the cicatrix remains destitute of hair and often of pigment. 



According to the testimony of Zundel and others, this mode of treat- 

 ing umbilical hernia is prompt and speedy. There is generally no occa- 

 sion to throw the animal down, and one assistant only is necessary ; it is 

 rarely followed by accidents. These do occur, however, and the most 

 serious and frequent is the escape of the intestines through the eschar, 

 about eight days after the nitric acid has been applied. This unfortunate 

 result has been attributed to excessive cauterization when the skin is thin 

 and fine, though it may also occur from the animal rubbing or tearing off 

 the sloughing cuticle when the pain or itching are troublesome. To ob- 

 viate this accident, Rev, Lafosse, Legoff, and others recommend the em- 

 ployment of a bandage, and quietude after the operation. Reynal has 

 observed peritonitis as a consequence of nitric acid cauterization, and 

 Lafosse mentions a case of tetanus due to this treatment. 



When the cauterization has not been sufficient, a relapse is likely to 

 occur ; Lafosse has observed one in twenty successful cases. This in- 

 sufficiency is generally noticed on the following day, in the absence or 

 trifling amount of swelling ; but the cauterization must not be attempted 

 again in less than two or three weeks. 



