LEAD-POISONING, OB PLUMBISM 227 



such poisoning also occasionally occurs in the domestic 

 animals. 



The soluble salts such as the nitrate and acetate, as well 

 as the peptonates formed in the stomach unite with 

 albumin to form a precipitate which is very slightly soluble 

 in excess of the salt. Thus lead salts do not penetrate 

 deeply but are among the most astringent of salts. Small to 

 moderate diluted doses do not irritate either the skin or 

 mucous membranes, but are astringent, desiccant, and 

 analgesic. They have a sweet rather than a corrosive taste. 

 When swallowed they act as gastro-intestinal astringents, 

 are absorbed very slowly, chiefly as albuminates, permeate 

 the tissues, contract arterioles to some extent, raise blood- 

 pressure, and slow the heart movements. Larger or long- 

 continued small doses irritate and then paralyse voluntary 

 and involuntary muscles through the motor-nerves, and also 

 affect the central nervous system. This action is illustrated 

 by the vomiting induced in dogs and cats, the cramp of the 

 intestinal and other muscles in man and animals, and the 

 paresis developed subsequently by toxic doses. These 

 effects appear to result from the local action of the lead in 

 the several textures affected. Hence arise, in chronic cases, 

 degeneration of the implicated muscles, chronic interstitial 

 nephritis, and cirrhosis of other internal organs. Certain 

 animals exhibit more prominently some of the actions of lead. 

 Muscular weakness and paralysis are well marked in frogs 

 and rabbits, are less pronounced in cats, and are absent in 

 dogs. Elimination is slowly effected in the urine, bile, and 

 intestinal mucus (Brunton). 



MEDICINAL USES. Lead is used medicinally only for its 

 astringent effects, and that when locally applied. It is 

 specially valuable as an intestinal astringent and styptic 

 with opium. It is of no use in cases of bleeding from the 

 lungs or kidneys, for it does not come in contact with the 

 part in sufficient concentration. 



Lead-poisoning, or plumbism, in the lower animals ex- 

 hibits symptoms analogous to those in man, and frequently 

 continues, in more or less aggravated form, for several 

 weeks, or even months. Digestion is impaired, appetite 

 becomes capricious and irregular ; there are spasms and 



