42 ELEMENTS OF PHYSIOLOGY 



result from depriving the body of these conditions. The 

 only possible way to return to health of the body is to 

 restore these conditions, and adapt the daily life to them. 

 The effect of various substances upon living cells may be 

 watched under a microscope. If bathed with a proper 

 food substance, the cell is seen to expand and grow and 

 move more actively. If bathed in an astringent substance 

 like the tannin of tea, it shrinks and ceases its movements 

 until revived. If bathed in a liquid to which a small quan- 

 tity of alcohol has been added, its activity ceases, and 

 unless the proportion is very small, such activity cannot 

 be restored. The chemical substances that actually attack 

 delicate living cells, causing them to shrivel, or decompos- 

 ing and destroying them, are called poisons. Arsenic de- 

 stroys the red blood cells. Strychnine attacks some of the 

 master cells, namely, the nerve cells, and their activity in 

 attempting to cast off the poison sometimes throws the 

 body into a spasm. The action of some poisons upon 

 cells, especially the nerve cells, is called 



70. Stimulation. This unnatural and exhausting ac- 

 tivity of the cells in their efforts to free themselves from 

 poison, is interpreted by some persons to mean that the 

 poison gives the strength and activity shown in the cells. 

 The poison does not put strength into the cells, but gets 

 it out, and honest food alone puts the strength back. 

 Alcohol hastens the breaking down of cell protoplasm 

 and lessens the activity of the tissue-building cells. This 

 is one reason why a person who has been used to alcoholic 

 drinks recovers less rapidly from an accident or surgical 

 operation than one who uses none. One of the first ques- 

 tions asked by a surgeon before operating, is whether the 

 patient uses alcohol. Tobacco also lessens the activity 

 of the cells that build and repair the tissues. This is the 

 reason why men who begin the use of tobacco when young 

 boys are often poorly developed and stunted in growth. 



