POISONS 331 



ing copious enough to show that an artery has been 

 cut, it will be necessary to apply pressure to check it. 



Poisons. Another frequent source of injury to the 

 tissues or of interference with their functions is found 

 in certain substances which are commonly known as 

 poisons. These may be taken into the body from with- 

 out, as in the case of drugs and chemicals ; or they may 

 be developed in the body itself by the action of microbes, 

 as ptomaines and toxins. 



Drugs and chemicals. Among drugs and chemicals, 

 there are several types of poison which differ widely 

 in their effects upon the body. Some destroy tissue, 

 as strong acids and alkalies, and are called corrosive 

 or irritant poisons. Others, as opium with its deriva- 

 tives and alcohol, produce their harm by benumbing 

 the nervous system and are therefore known as narcotic 

 poisons. A third type, as strychnia, excites the nervous 

 system so much as to destroy its control of the body and 

 thereby cause convulsions. Poisons of this kind are 

 therefore called convulsive. The effects of drugs and 

 chemicals are sometimes very quick or again so slow 

 as to extend over weeks and months, depending largely 

 upon their nature and the quantities in which they are 

 taken. Since many of the substances in common use 

 in the household, such as disinfectants, insect powders 

 and the like, are, when taken into the body, violent 

 poisons, every one should be acquainted with them and 

 their antidotes. 



General treatment: 



1) Send for the nearest doctor. 



2) Produce vomiting by the use of: 

 Finger or feather for tickling the throat. 



Mustard water, tablespoonful of mustard in tumbler of tepid 

 water. 



