.•2IO The Management dnd Diseases of the Dog. 



cury, variously diluted ; for example, the nitric oxide of 

 mercury, unguentum hydrargyri nitratis, and unguentum 

 'hydrargyri ammonio-chloridi. In some forms of chronic 

 eczema one or other of these ointments is specific ; for 

 ■example, the unguentum hydrargyri, nitrico-oxydi diluted 

 to the extent of one part in four, in pityriasis capitis ; the 

 unguentum hydrargyri nitratis, one part in eight, in psoriasis 

 palpebrarum, etc. Sometimes eczema rubrum and eczema 

 iimpetiginoedes, when of long continuance, or when the 

 water-dressings or poultice have been unduly prolonged, 

 ibecome excessively tender, so tender in fact, as to be irri- 

 tated by the mildest application. I have such a case in 

 remembrance, wherein the disease of the skin was rendered 

 most distressing by its associations with a kind of cutaneous 

 neuralgia ; and I have since seen several cases of a similar 

 kind. In this morbidly sensitive state, of the skin and of 

 the eruption, I have found no remedy act so well as a solution 

 of nitrate of silver in distilled water, in the proportion of 

 one grain to the ounce."* 



In such cases, constitutional treatment is not to be over- 

 looked. Small doses of arsenicum or calomel are attended 

 with considerable benefit, iron and quinine also are of ser- 

 vice. The animal should be kept dry, and the bedding 

 clean. Exercise and nutritious feeding must likewise be 

 observed. 



A species of eczema is not unfrequently produced through 

 the incautious use of mercury (eczema mercuriale or hydrar- 

 gyria). " An eruption occurs, characterised by round irri- 

 table patches of skin from which a secretion oozes, and 

 which are denuded of hair. The skin is at first red, swollen 

 and afterwards rough and hard. In dogs the eruption 

 occurs chiefly on the limbs and scrotum. The general 

 symptoms are loss of appetite, salivation, closure of the 



* Wilson's " Diseases of the Skin," p. 191. 



