A few pounds (3 to 5) of common salt will produce well-marked signs of poisoning in cattle. So much salt as this will not be taken by cattle except under unusual conditions. If the feed is poor in salt, and if no salt has been given for a long time, an intense "salt hunger" may occur that may lead an animal to eat a poisonous quantity, or an overdose of salt may be given by error as a drench. In order to prevent overeating of salt, it is doubtless better in salting cattle to use rock salt rather than that in more or less finely divided form. Herring and mackerel brine and pork pickle are also poisonous, and are especially dangerous for hogs. In these substances there are, in addition to salt, certain products extracted from the fish or meat which undergo change and add to the toxicity of the solution. Sometimes saltpeter is present in such brines. _Symptoms._--The symptoms are great thirst, abdominal pain, diarrhea, poor appetite, redness and dryness of the mouth, increased urination, paralysis of the hind legs, weak pulse, general paralysis, coma, and death in from six to eight hours. _Treatment._--Allow as much warm water as the animal will drink; give protectives, such as linseed tea, etc. Linseed or olive oil may be given. To keep up the heart action give ether, alcohol, camphor, digitalis, or coffee. To allay pain, give opium. VEGETABLE POISONS. Vegetable poisons may be divided into two classes--those that are likely to be administered to the animal as medicine, and such as may be taken in the feed, either in the shape of poisonous plants or as plants or feeds of vegetable origin that have been damaged by fungi or by bacteria which have produced fermentation or putrefaction. VEGETABLE POISONS USED AS MEDICINE. OPIUM (MORPHIN, LAUDANUM) POISONING.