i 7 6 INFECTION AND IMMUNITY 



person. The bacillus may also retain its vitality for 

 one hundred days or more in putrefying material. 

 This bacillus has also greater resistance to heat and 

 various germicidal agents than most other pathogenic 

 bacteria. But it is quickly killed by exposure to the 

 temperature of boiling water ; by a five-per-cent. solu- 

 tion of carbolic acid ; by a two-per-cent. solution of 

 chloride of lime ; by milk of lime, solution of caustic 

 potash (lye), or the mineral acids a one-per-cent. 

 solution of sulphuric or hydrochloric acid. Wood 

 vinegar, or pyroligneous acid may also be used if at 

 least six hours' time is allowed for disinfection. 



What has been said with reference to predisposing 

 causes will indicate the measures which should be 

 taken to increase the resistance of individuals to in- 

 fection especially of those who have an inherited or 

 acquired feebleness of constitution. An out-door life, 

 systematic exercise, and a nutritious diet will be the 

 main factors in establishing a relative immunity to 

 the disease. Children with narrow chests and insuf- 

 ficient lung capacity should be required to take breath- 

 ing exercises as prescribed by Dr. Knopf, of New 

 York. 



" The patient is taught to stand properly that is to say, 

 straight, chest out, and head erect and to breathe always through 

 the nose. He takes a deep inspiration slowly, beginning with the 

 abdominal muscles, and then expanding the chest to its fullest 



