472 SPOEAPIC DISEASES. 



Lead poisoning is a disease generally confined to those dis- 

 tricts of the country where lead smelting is carried on. It may, 

 however, occur accidentally in any part where animals have 

 access to lead paint, or splinters of leaden bullets, which are often 

 scattered about in quantities near rifle targets. It also occurs in 

 cattle pastured in fields manured with town ashes, which often 

 contain scrapings of paint-pots, waste paint, &c. 



In whatever form the lead gains access to the stomach, it 

 must be rendered soluble before it is absorbed into the circula- 

 tion. Lead paint, leaden bullets, and other insoluble forms of 

 lead, are acted upon by the acid secretion of the true digestive 

 stomach, and are thus rendered soluble and fit for absorption 

 into the animal economy. The portions of insoluble lead found 

 in the rumen, &c. of horned cattle are to be looked upon as 

 indicating that lead is present, and that some of it is absorbed into 

 the system, rather than as actual causes of any symptoms pre- 

 sent prior to death. Lead in its metallic state appears to be 

 devoid of medicinal or poisonous action. Four ounces of shot 

 were given to a dog at the Veterinary School of Lyons without 

 effect. The metal may sometimes, however, be converted with- 

 in the body into an oxide or active salt. — (Finlay Dun.) Shot 

 is used by low horse-dealers to relieve the symptoms of broken 

 wind, and doubtless some of the lead is dissolved by the gastric 

 acids, and acts as a sedative upon the gastric nerves. 



Plumbism, or lead poisoning, results from the absorption of lead 

 into the circulation. It is thus diffused through the whole body, 

 and exerts its toxic action upon all the organs and tissues of the 

 animal frame, but it does not affect all parts aUke, but accumu- 

 lates in some more than in others. 



Dr. George Wilson (see Monthly Journal of Iledical Science, 

 May 1852), found that the spleen yielded lead most abundantly ; 

 next to the spleen the liver yielded most ; then the lungs, after- 

 wards the kidneys, then the heart, and the intestines least. Lead 

 has also been found in the brain and in the muscles ; and the blue 

 line observed in the gums of animals and men poisoned with lead, 

 is supposed by Toures to be due to the lead in combination with 

 the tartar of the teeth. 



Lead having once entered the body, leaves it very slowly, 

 and may be detected in it months after an animal has ceased to 

 receive lead with its food or water. It enters into combination 



