782 



THE MONTHLY BULLETIN. 



affects the point with which it comes in contact; for instance, the irri- 

 tation of mucous membranes caused by arsenic. An effect is remote 

 when a distant part of the body is involved. A poison may be taken 

 into the stomach, but the resultant effect may appear in the spinal 

 cord, as in the case of strychnine. The poison has to be absorbed and 

 carried by the blood to the part affected. Local action usually causes 

 a slow death accompanied by intense suffering ; the remote causes death 

 more quickly without such severe pain. The latter group of poisons 

 has proved more satisfactory for use in poisoning operations. Death 

 in either case is caused by collapse produced by the sudden change 

 made in the structure of the affected part, or by disruption of its natural 

 way of functioning. 



The quickness with which poisons act depends first on the poison; 

 second, on the form and manner in which it is administered ; and, third, 

 on the individual animal itself. Naturally some poisons act more rap- 

 idly than others, but the poison may act more quickly as a gas than 

 as a liquid or a solid; for example, carbon disulphid. Generally speak- 

 ing, the more finely the poison is divided the easier and quicker its 

 absorption and action. A small lump of phosphorus might be taken 

 into the stomach and pass through the body without serious result, but 

 if a very small part of that lump finely divided or in solution were 

 taken, it might cause death very quickly. Again, the same poison 

 varies in rapidity of action in different individuals of the same species. 

 Usually poison acts more quickly on a young than on an old animal, on 

 an animal in a weakened physical condition than on one that is strong, 

 healthy, and vigorous. "When taken into an empty stomach, poison 

 acts more quickly than when received in one containing considerable 

 food. The character and amount of the stomach contents may accel- 

 erate or retard action. A poison taken directly into the blood acts 

 more quickly than by way of the stomach. Some poisons, if at first 

 taken in small doses, may later be increased in amount until the dose 

 in larger than that which is ordinarily fatal and still not cause serious 

 results. This is true of arsenic. It is difficult to state with certainty 

 fatal doses of any poison because of the many conditions affecting 

 their action. Poisons properly used are certain in action and are the 

 most reliable means of destroying rodent pests. 



A few important points regarding the chief poisons now in use may 

 be summarized as follows: 



PHOSPHORUS. 



Effect — Local in action, first causing irritation and inflammation of the digestive 

 tract. Death may occur in the early stage of poisoning, but usually in man 

 there is temporary recovery, followed in a few days by recurrence of the symp- 

 toms, accompanied generally by jaundice and severe abdominal pain, resulting 

 eventually in collapse and death. 



Fatal Dose — Minimum dose for a human being may be one-fourth to three-fourths 

 grain. 



Advantage — Small dose effective if given in a finely divided or soluble state. 

 Objections 



1. It is slow in action. 



2. It is dangerous to handle by the inexperienced because of its inflammability 



when exposed to air and sunlight. 



3. It is no respecter of useful birds or animals, but kills all alike. 



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