294 MERCUROUS CHLORIDE 



in the state of metallic sulphide and sulphate exerting an 

 antiseptic effect, and usually imparting a green colour to the 

 faeces by preventing decomposition changes in the bile. The 

 opinion that calomel undergoes partial conversion into the 

 higher chloride before absorption is not supported by 

 evidence, and such a change is unnecessary, for the proteid 

 present is sufficient to dissolve it and form the albuminate. 

 It is likely that leucocytes may take up particles of the salt 

 and transport them through the bowel wall, just as they do 

 when calomel is injected subcutaneously. 



Toxic EFFECTS. Calomel is less irritant than mercuric 

 chloride or nitrate, but irritant effects, usually followed by 

 constitutional disturbance, are produced in horses by three 

 or four drachms ; in cattle by two or three drachms ; in 

 sheep by fifteen to thirty grains ; in dogs by six to thirty 

 grains. Hertwig found that these doses, within twenty-four 

 or thirty-six hours, and in dogs in less time, caused occa- 

 sional colic and copious discharge of faeces, which contained 

 bile, and were greyish-green in cattle, but darker in dogs. 

 Such doses, especially if repeated daily for three or four 

 days, further induce fluid and stinking evacuations, foetid 

 breath, soreness of the mouth, rapid impairment of appetite 

 and condition, and fatal low fever and dysentery. 



At the Edinburgh Veterinary College a healthy donkey 

 was given a drachm of calomel daily in three separate doses. 

 About the sixth day the animal became excitable, and the 

 pulse rose to 85. By the eighth day secretion of saliva was 

 augmented, the breath was foetid, the gums red and tender, 

 and appetite impaired ; but the fseces and urine were normal. 

 By the twelfth day these symptoms became more aggravated, 

 the pulse softer and less frequent, the strength much reduced. 

 On the fourteenth day administration of the calomel was 

 suspended, but death occurred two days later. The animal 

 had received fourteen drachms in fourteen days. Post- 

 mortem examination discovered the teeth loose, the mucous 

 membrane of the mouth and air-passages blanched, while 

 that of the stomach and intestines was softened, easily torn, 

 and in many places thickly covered with mucus. The liver 

 was rather friable, but the kidneys, spleen, and lungs were 

 healthy. 



