476 SPORADIC DISEASES. 



Wlien the bowels are iliorouglily acted upon, and if the sul- 

 phuric acid does not seem to agree with the animal, sulphur and 

 vegetable tonics may be substituted. The sulphur is partially 

 transformed into sulphuretted hydrogen, which combines with 

 the lead, and forms an insoluble sulphide. 



In the slower form of lead poisoning, and where the lead has 

 been slowly accumulating in the system, it will be well to con- 

 sider the chances of success before attempting a cure ; and 

 in none but the mildest cases should this be attempted, as the 

 termination will prove neither creditable to the practitioner nor 

 profitable to the owner. 



In all cases a small dose of the sulphate of magnesia is to be 

 administered, and when this has operated, the elimination of the 

 poison is to be attempted by the iodide of potassium. 



The principle upon which the iodide of potassium acts has 

 been pointed out by Melseus, who assumes that the lead is 

 retained in the body as an insoluble compound with the tissues. 

 The iodide, after its absorption into the blood, combines with the 

 lead, and forms with it a new and soluble salt. The poison is 

 thus liberated from its union with the injured part, dissolved 

 out from the damaged fibre, and once more set afloat in tlie 

 circulation, and along with the remedy cast out with the urine. 

 Great caution is at first necessary in using this remedy, as at 

 the moment when the compounds, fixed in the body, become 

 dissolved or transformed, the phenomena of acute poisoning may 

 occur. The dose must therefore be small at first, and either 

 increased or diminished, as the patient seems to bear it. 



Galvanism is also recommended for lead poisoning in man ; 

 and, if necessary, may be tried in tlie case of a valuable horse 

 or cow. 



It will be apparent tliat removal of animals from the source 

 whence the lead is obtained must be the first step in the 

 treatment. 



The soluble salts of lead, such as the acetate, when given in 

 poisonous doses, cause nausea, quick, small, hard pulse, colic, 

 stiffness of the limbs, paralysis of the optic nerves, insensibihty, 

 and death ; and on post mortem examination the gastric mucous 

 membrane is found reddened from congestion, or grey, and 

 liaving a macerated appearance, owing to the chemical action of 

 the salt. 



