148 The Evolution of Medical Science. 



fer other tissues of the body. Of those that are found in 

 or upon the human body, but a small proportion are in any 

 way responsible for disease. These we distinguish as 

 pathogenic. Of all pathogenic micro-organisms (or, as ab- 

 breviated, microbes) those of consumption are perhaps the 

 worst.* Now we know they exist, and sanitary science 

 clearly points out certain duties for us to perform, for self- 

 protection, that are yet sadly neglected. People get con- 

 sumption only by contagion from consumptives. It is not 

 hereditary. Weak lungs are hereditary, but weak-lunged 

 people, kept away from consumption-germs, will never take 

 the disease, even if their fathers and mothers, sisters and 

 brothers, uncles and aunts all died from it. If they 

 breathe the confined air of the consumptive's room, they 

 will take it ; if they eat under-cooked meat from consump- 

 tive cattle, they will take it ; and if they drink milk from 

 consumptive cows they are likely to take it. If their con- 

 sumptive friends spit indiscriminately around, and the 

 sputa drys and is wafted into the air for them to breathe, 

 tluey will take it. Sanitary Science demands the burning 

 of the consumptive's spittle, the boiling of all doubtful 

 milk, and thorough cooking of all doubtful meat, and tlie 

 perfect ventilation and thorough cleaning of walls, ceilings 

 and floors, of all rooms once occupied by consumptives, 

 with deluges of water. 



The pathogenic microbes of typhoid-fever bear some re- 

 semblance to those of consumption. They develop in 

 glands of the intestines known as Feyer's glands. The 

 only source of contagion from such patients is in their de- 

 jecta. In country places, this disease is spread by the 

 spores being washed through the soil from their outdoor 

 closets down into the underground streams of water that 

 supply their wells. Xut only typhoid-fever germs, but 

 Asiatic cholera, the summer cholera of children, and a 

 large number of minor ailments cliaracterized by diarrheas, 

 are propagated in the same way. Country farmers, in 

 watering the milk of city customers, send these diseases 

 into the city through this channel. This is another reason 

 why milk of unknown origin should be boiled before 

 drinking. 



In large cities, the outdoor-closet nuisance is abated, and 

 the bath-room closet tak(>s its place. Here a system of 



* Cruikshiiiik'a IJactoriology, p. l.V.l. 



