THE SKIN. 209 



sorbed, and convey the disease to any one who should next 

 sleep in that bed or wear that garment which had been thus 

 infected. The poison of dogwood or ivy is absorbed by the 

 skin of the susceptible, if they but touch the plant; and the 

 disease, being excited within the skin, extends beyond the 

 point of contact, and sometimes over the whole surface. 



498. The poison of bad air is supposed to be thus ab-' 

 sorbed. In marshy countries, where the exhalations from 

 the earth infect the atmosphere with the seeds of fever 

 or other disease, the people whose lungs breathe, and whose 

 surface is in contact with this air, receive the poison by 

 the absorbing power of their skin and their air-cells 



499. This absorbing power is more active at night : then 

 contagion of disease and infection of bad air act with more 

 readiness and vigor, and men are more liable to be attacked 

 by prevailing epidemics through the air, or by contagious 

 diseases from contact with those already diseased, than in the 

 daytime. It is more active when the body is badly nour- 

 ished than when it is well fed. Hunger and thirst increase 

 the absorbing power of the skin, and good nutriment 

 diminishes it. So that one is more susceptible of disease 

 before than after breakfast, (113, p. 56;) and cautious 

 physicians fortify themselves with nourishment in the morn- 

 ing, before they visit patients who are suffering from epi- 

 demic or oontagious diseases. 



500. Any poisonous or offensive matter in contact with 

 the surface stimulates the cutaneous absorbents. The nat- 

 ural excretions of the skin, the perspiration, the oil, and the 

 dead cuticle, being the offensive waste of the body, if not 

 removed from it, excite this tendency to absorption ; and 

 when they are not washed away, or are confined too much by 

 impervious clothing, they themselves are often taken back, to 

 irritate and disturb the system. 



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