22 LABORATORY LESSONS IN GENERAL SCIENCE 



body often act on the tissues as poisons, or toxins. They are 

 destructive of the life of the tissues. Remedies that coun- 

 teract the effects of these products, or that prevent their 

 formation by preventing multiplication of the germs, are 

 called anti-toxins. 



To secure immunity against what diseases are persons 

 vaccinated ? For what ones are serums administered ? 



4. When the skin on the body is cut or torn, germs 

 may find lodgment in the wound. Their development and 

 multiplication may cause an unnatural secretion called pus. 

 This pus, and the toxins it contains, when absorbed into the 

 blood and circulated throughout the system may cause 

 blood poisoning. Aside from the desire to relieve pain 

 caused by pressure, why is a physician or surgeon often 



employed to lance any seri- 

 ous swelling, e.g., a boil? 

 Various substances, applied 

 promptly to wounds and to 

 bandages used, either destroy 

 the germs or make conditions 

 unfavorable to their growth 

 and development. Such sub- 

 stances are called antiseptics. 



-Sterilisation by boning. ( ^ c hag reference to pu _ 



trefaction of animal tissue.) Modern surgery owes much of 

 its success to the use of antiseptics. Where the tissues of a 

 wound are kept free from germs and in a healthy state, 

 rapici healing is possible. 



The absolute destruction of the life of these germs, whether 

 by action of chemicals or by high temperatures, is called 

 sterilization. The surgeon is exceedingly particular in all 



