Human Physiology. 



meals may be eaten without injury by a few persons with quick 

 digestions; but, as a rule, there should be five or six hours 

 between our meals, and few persons can eat within six hours of 

 bedtime without being the worse for it. A late meal disturbs 

 the whole alimentary system, when it ought to be at rest. It 

 produces irregular action of the brain, with unpleasant dreams 

 and nightmare; causes amative excitement, loss, and exhaus- 

 tion ; after a troubled sleep a weary wakening, with fever and 

 thirst, headache, languor, loss of appetite, and various dyspeptic 

 symptoms ; tendencies to heart disease and apoplexy. Bad 

 feeding and over-feeding are the direct causes of most of the 

 diseases of the stomach, intestinal canal, liver, and kidneys, 

 .and the indirect cause of many diseases of the heart and circu- 

 lation, and of the brain and nervous system. 



Condiments of a heating and stimulating character, as pep- 

 pers, spices, sauces, relishes, are causes of disease by stimu- 

 lating to excess. They excite appetite and digestion ; but all 

 stimulants weaken and destroy the nervous power they excite. 

 We must take more and more, and finally they fail to act, and 

 leave us helpless and wretched. "Hunger is the best sauce." 

 A healthy appetite needs no stimulation. 



Bad water, and bad drinks taken in the place of water, which 

 are, in fact, water with more or less noxious additions, are 

 causes of disease. There are some striking facts which illus- 

 trate the influence of pure water in preserving health, and of 

 impure water in generating disease. Typhoid fevers are traced 

 to wells near leaking sewers or cesspools. Many cases of 

 cholera in London were believed to have been caused by 

 drinking the water of particular wells, which was found to be 

 tainted with sewage. In one attack of cholera, mostly confined 

 to a district of East London, the population had been supplied 

 for a time with water largely mixed with sewage. But the 

 river Thames itself, which supplies a large part of the metro- 

 polis, is the common sewer of hundreds of thousands of people 



