MINEEAL OE INOEGANIC POISONS 61 



I 

 mill, milk, and burnt magnesia may be used. Besides 



elimination of the cause, mucilaginous and stimulating 



medicines are indicated. 



Chemical Diag'nosis. — The separation of copper from 

 organic tissues follows the course indicated under the 

 general scheme. 



Delicate tests are — the formation of a dark blue liquid 

 with excess of ammonia, and the formation of the reddish- 

 brown ferrocyanide by means of potassium ferrocyanide 

 in the presence of acetic acid. The latter test is of excessive 

 delicacy, showing the presence of copper in insufficient 

 quantity to respond to the ammonia test. From the 

 remarks made above, it is evident that the detection of 

 copper in the liver and kidneys is no evidence of copper 

 poisoning, but its presence in the stomach contents of the 

 herbivorse, or in the vomit or faeces of a dog will, if the 

 quantity is considerable, point to copper as the particular 

 agent of the observed corrosive poisoning. 



ZINC. 



Forms and Oeeuprence. — Although metallic zinc and its 

 compounds are widely encountered, the poisoning of animals 

 by them is a rare event. The sulphate (white vitriol) finds 

 use as an emetic, and is liable to be mistaken for Epsom 

 salt, which has the same crystalline appearance. The 

 chloride is a very soluble and deliquescent substance, having 

 a powerful corrosive action, and is not given internally. 

 The solution in water is faintly acid in reaction, and con- 

 stitutes Burnett's fluid, used as a strong disinfectant for 

 unheathly wounds. A concentrated solution of zinc chloride 

 is used in plumbing, and a mixed solution of the chloride 

 with sulphurous acid used to be employed as a disin-' 

 fectant (Tuson). 



Each of these salts is irritant, and causes poisoning. 

 The double salts with potassium or ammonium are less 

 powerfully irritant. 



