POISONS AND POISONING. 67 



every four or five hours, arid the application of cold water to the head. 

 Dilute sulphuric acid in half-ounce doses should be given with the pur- 

 gative medicine. In this case sulphate of magnesia (Epsom salts) is 

 tin- best purgative, and it may be given in doses of from 1 to 2 pounds 

 dissolved in warm water. After the acute symptoms have abated, 

 iodide of potassium may be given in doses of 2 drains each, three times 

 a day for a week. 



Chronic lead poisoning occasionally occurs in districts where lead 

 mining is the principal industry. The waste products of the mine 

 thrown into streams contaminate the water supply so that the mineral 

 is taken into the system gradually, and a very small per cent of any of 

 the salts taken into the system in this way is pernicious. Water which 

 contains any salt of lead to the extent of more than one-tenth of a grain 

 to the gallon is unfit to drink. It may be conveniently tested by plac- 

 ing it in a white porcelain dish and adding a few drops of sulphureted 

 hydrogen, when if the lead be present the color of the dish will be dark- 

 rm-il. Such water when used continually is likely to produce colic 

 from the resulting intestinal irritation and in aggravated cases paralysis 

 more or less severe is likely to be developed. A blue lino on the mar- 

 gin of the gums, the last symptom, is regarded as diagnostic, and its 

 presence as conclusive evidence of the nature of the disorder. The free 

 use of purgatives is indicated with iodide of potassium. No treatment 

 is likely to be of avail until the cause is removed. 



COPPER POISONS. 



The soluble salts of copper, though used as a tonic in the medicinal 

 treatment of cattle, are poisonous when taken in large quantities. Like 

 lead and arsenic they have an irritant effect upon the mucous mem- 

 brane with which they come in contact in a concentrated form. Cattle 

 are not very likely to be poisoned from this cause unless through care- 

 lessness. The salts of copper the most common of which is the sul- 

 phate of copper, commonly called blue vitriol are occasionally used 

 for disinfecting and cleansing stables, where they might inadvertently 

 be mixed with the food. In animals having the power to vomit it acts 

 as an emetic and tends to work its own cure. Cattle, however, al- 

 though ruminants and having power to return parts of the food to the 

 mouth for remastication, are unable to empty the stomach in this way, 

 so that when large quantities have l>een taken the tine of the* Ntomach- 

 pump is at once indicated. This should be followed by a liberal supply 

 of demulcent**, linseed infusion, boiled starch, whites of eggs, etc. 

 The general symptoms produced are those of intestinal irritation, short 

 breathing, stamping, and tender abdomen. 



ZINC POISONS. 



Several of the soluble salts of y.inc are irritant poisons. In iinimnln 

 which have power to vomit they are emetic in their action. In others, 



