POISONS. 195 



plant, grows on banks exposed to the sun. When an 

 excessive dose of this special cardiac sedative has been 

 administered it causes irritation of the alimentary canal. 

 The symptoms are those characteristic of a sedative 

 poison, together with a peculiarly violent action of 

 the heart, and subsequently diuresis. Signs of irrita- 

 tion of the alimentary canal are visible post mortem, and 

 the heart is soft and ecchymosed. Agents containing 

 tannin are suggested as antidotes. 



Lead, when taken into the system, acts as a local 

 and general sedative. This metal and its salts are highly 

 important to us from a toxicological point of view. It 

 may gain entry in the water, since several of the com- 

 pounds of lead are soluble, from the lead diffused in a 

 state of minute division over the pastures near smelting 

 works or near rifle butts, or from refuse paint brought 

 with manure and spread over fields. These lead salts are 

 sweet, so that cattle readily consume them. In some 

 cases of lead poisoning there is indigestion with colic, due 

 to paralysis of the stomach in which food accumulates, 

 and tympany sets in ; this is accompanied by general signs 

 of disease, depression, and a small pulse. Later, deposits of 

 lead may be seen, of a greyish colour, in the gums. There 

 is paralysis throughout the alimentary canal, paralysis of 

 the hind limbs sets in, and the animal dies after a some- 

 what prolonged illness. On post-mortem examination the 

 hardened condition of the intestinal and gastric contents 

 may be noted, and the blackness or reddened state of 

 the mucous membrane. The presence of lead may be 

 shown in many of the tissues. Sulphuric acid and the 

 sulphates of soda or magnesia and alum are the best che- 

 mical antidotes, forming the insoluble lead sulphate. 

 Cathartics must be given to remove the poison. In other 

 instances lead produces the symptoms of '^stomach 

 staggers,^^ with a slow pulse, delirium, and death. 



Laburnum, as described by Dobson, seems to act as a 

 sedative poison, producing paralysis of the hind limbs, and 

 an accumulation of food as a dense mass in the rumen. 

 Besides the special characters of their contents there may 



