ACTION OF ARSENICAL COMPOUNDS 173 



less as urea. Poisoning causes degeneration of the bone marrow and 

 anemia^ also widespread fatty degeneration of the tissues. Large doses, 

 on the other hand, increase metabolic processes and the escape of nitroge- 

 nous waste. 



Elimination.- — Arsenic is eliminated slowly by most channels, but 

 mainly by the urine and to a less extent by the mucous membrane of the 

 respiratory and digestive tracts. Traces are found in the milk, sweat, 

 tears and saliva. It exists in, and can be recovered from, the bodies of 

 animals years after their death from toxic amounts of arsenic. 



Summary. — Arsenic is unfortunately one of the drugs whose physio- 

 logical action — so far as we know it — does not throw any light, in many 

 instances, upon its therapeutic effects. Clinically arsenic improves the 

 general condition and increases the number of red blood cells or prevents 

 their destruction (by destroying a causative organism of anemia in the 

 blood) in pernicious anemia, and lessens the number of leukocytes^in the 

 blood in leukemia, thus producing results directly opposite to experimental 

 findings. In altering the condition of the patient for the better, in some 

 diseases, it is described by that vague and otherwise indefinable term, 

 "alterative." 



Toxicology. — The lower animals, as the horse and cow, are propor- 

 tionately not nearly so susceptible to the poisonous effects of arsenic as 

 the human subject; 1^ grains is the smallest fatal dose reported in man. 

 An amount as large as one dram of arsenous acid in solution is required 

 to cause death in a horse or cow, although much smaller quantities have 

 produced death when repeated a number of times (two daily doses of 45 

 gr., four daily doses of 30 gr. have proved fatal to horses). One-half 

 ounce to an ounce and a half of white arsenic is the toxic single dose for 

 the horse and cow, and from one to two drams for sheep — with consider- 

 able variations. Dogs have been killed by 2 grains; hogs by 15 grains. 

 Mild toxic action is seen following therapeutic doses of arsenic when the 

 physiological limit is reached. This condition is characterized by loss of 

 appetite (nausea and vomiting in dogs), watery discharge from the nose 

 and eyes, puffiness of the eyelids, indigestion with mild colic, and diar- 

 rhea. The pulse may be accelerated and harder than normal. The 

 appearance of albumin in the urine is the surest sign that arsenic has been 

 pushed past the safe physiological limit. 



Acute Poisoning begins with bilious, mucous, or bloody purging and 

 colic. There is vomiting in dogs. Thirst is excessive ; the urine is high- 

 colored and albuminous ; the pulse is feeble, small and frequent ; the 

 respiration is rapid and difficult from abdominal pain; the extremities are 

 cold, and there is great weakness of the limbs. Collapse, with convul- 

 sions and coma, often close the scene in from five to twenty hours to 

 three days. 



A sub-acute form of poisoning occasionally occurs after a remission 

 from the acute attack, only to be followed by death in from two to five 

 days. In the interim, cutaneous eruptions may appear. Rarely, death 

 takes place within an hour or two, in coma, collapse or convulsions. 



Chronic Poisoning is seen in the human subject living in apartments 



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