ITS PRACTICAL VALUE TO THE GENERAL PRACTITIONER. 11 



The claims made that the bacteria causing mumps, scarlatina 

 and whooping-cough have been isolated, do not, as yet, appear 

 conclusive; while the organisms of such notably infectious dis- 

 eases as typhus and small-pox await discovery. The better 

 knowledge of the bacteria producing the infections has been fruit- 

 ful in improving hygienic measures a subject too extensive to be 

 considered at this time. Not less important have been the re- 

 flections of etiologic advances in improvements of diagnosis, 

 prophylaxis and treatment. 



Bacteriologic Diagnosis. Having ascertained that a micro- 

 organism is invariably found in the body in association with a 

 single disease and with that disease only, the diagnosis of the dis- 

 ease may readily hinge upon the determination of the presence 

 of the bacterium. The chief methods used to determine the char- 

 acter of u micro-organism, 'and thus diagnose the disease, depend 

 upon: (1) Peculiarities in form and arrangement; (2) peculiari- 

 ties of staining; (3) peculiarities of cultural growth; (4) pecul- 

 iarities of effects produced when introduced into the bodies of 

 certain animals; (5) peculiarities in behavior of cultures of the 

 micro-organism when brought in contact with certain fluids from 

 the diseased animals. 



Certain of the higther forms of the vegetable parasites, es- 

 pecially the parasitic moulds and yeasts, are readily recognized by 

 their peculiarities of form -alone. For example, the sacchar- 

 omyces <albicans of thrush and the varieties of aspergilli found in 

 the external ear are readily determined by microscopically ex- 

 amining some of the suspected material in a drop of -an indiffer- 

 ent fluid; while an accurate diagnosis of the varieties of ring- 



