THE DIAGNOSIS OF ASIATIC CHOLERA. 469 



upon the value of microscopic examination in these cases 

 as follows : 



a. In the majority of cases microscopic examination 

 is sufficient for the detection of the presence of the 

 comma bacillus iu the intestinal evacuations of cholera 

 patients. 



b. Even in the most acute cases, running a very rapid 

 course, the comma bacillus can always be found in the 

 evacuations. 



c. In general, the number of cholera spirilla present 

 is greater the earlier death occurs ; when death is de- 

 layed, and the disease continues for a long period, 

 their number is diminished. 



d. Should the patient not die of cholera, but of some 

 other disease, such as typhoid fever, that may be en- 

 grafted upon it, comma bacilli may disappear entirely 

 from the intestines. 



2. From another slimy flake prepare a set of gelatin 

 plates. Expose them to a temperature of from 20° to 

 22° C, and after sixteen, twenty-two, and thirty-six 

 hours observe the appearance of the colonies. Usually 

 after about twenty-two hours the colonies of this organ- 

 ism can easily be identified by one familiar with them. 



3. With another slimy flake start a culture in a tube 

 of peptone solution — either the solution of Dunham 

 or, as Koch proposes, a solution of double the strength 

 of that of Dunham (Witte's peptone is to be used, as it 

 gives the best and most constant results). Keep this at 

 from 37° to 38° C, and at the end of from six to eight 

 hours prepare cover-slips from the upper layers (without 

 shaking) and examine them microscopically. If comma 

 bacilli were present in the original material, and are 

 capable of multiplication, they will be found in this local- 



