316 THE AMERICAN MONTHLY [Oct. 



cillus in Asiatic cholera, bacillus aathracis in malignant 

 pustule or wool-sorter's disease, bacillus pneumoniae of 

 Friedlaender in pneumonia, the plasmodium malarise in 

 malarial fever, the spirillum of Obermier in relapsing 

 fever, the bacillus of Eberth in typhoid fever, the Klebs 

 Loefiler bacillus in diphtheria, the bacillus mallei in 

 glanders, the bacillus of Nicobaer in the secretions of 

 wounds of those suffering with tetanus, and what shall I 

 say more, for the time would fail me to go into an ex- 

 tended consideration of this important subject. So with 

 this introduction I will ask your attention to a few exam- 

 ples of the practical application of the microscope in 

 diagnosis and prognosis. 



EXAMINATION OF SPUTA. 



Dried cover glass stained preparations must be made. 

 Since Robert Koch's discovery of the bacillus tuber- 

 culosis in 1884, their presence in the sputa has been con- 

 sidered by all observers to be of great diagnostic 

 value, and indeed when found in quantity are positive 

 evidence of tubercular disease somewhere in the respir- 

 atory tract or in the lungs, and yet, they may be found 

 in the sputa and the case not be a hopeless one ; one 

 swallow does not make a summer, yet it might indicate 

 its near approach, neither does the finding of one ba- 

 cillus in the sputa of a suspected case prove it to be one 

 of tuberculosis. Again, if the bacilli are found in the 

 phagocytes only, and not free, and there is no indica- 

 tion of destruciion of tissues present in the sputa under 

 examination, a favorable diagnosis and prognosis can be 

 made, for it is evident the system is taking care of itself 

 to a great extent and with good hygienic conditions and 

 proper treatment the patient will in all pi'obability 

 recover. 



But if the bacilli are found free and contain spores 

 and associated with si)ores indicating the vigorous 



