CHOLERA 91 



length (comparing it with a red blood-corpuscle) and the'number of 

 turns of which this distance is made up. If there are about six 

 or eight turns to this distance, it is almost certainly pallida ; if 

 there are fewer, it is not. Examine its ends, and see whether they 

 taper off to a point or terminate abruptly. 



It is also possible to see the spirochaste unstained, when it is 

 actively motile, but it is not possible to distinguish it from its 

 congeners in this way without much practice. In point of fact 

 practice is an essential in the diagnosis of syphilis by the recognition 

 of the spirochaete, and the practitioner is recommended to identify 

 the organism as often as he can in undoubted cases before 

 attempting its recognition in doubtful ones for diagnostic purposes. 



CHOLERA 



The diagnosis of cholera can only be made on clinical grounds 

 alone during an epidemic, as other diseases present almost 

 identical symptoms and course. The importance of making a 

 correct diagnosis arises less from the interests of the patient than 

 from those of the general public ; if the case is one of true Asiatic 

 cholera, the sanitary authorities must be notified and the fullest 

 precautions taken to prevent the spread of the disease. In all 

 suspicious cases a quantity of the rice-water stools (in a bottle 

 sterilized by boiling or by dry heat and securely packed) should be 

 forwarded at once to a public laboratory. Meanwhile the 

 diagnosis may be established with a fair amount of certainty by 

 the following simple tests : 



1. Take a platinum loopful of the dejecta and spread it in a 

 thin film on a clean slide ; dry, fix, and stain with carbol fuchsin 

 for three minutes ; wash, dry, and mount. 



2. Prepare another film and stain by Gram's method. 



Examination of the Films. 



The spirillum of Asiatic cholera is about half as long as a 

 tubercle bacillus, or rather longer, and much thicker. It is 

 slightly curved : hence the name of the " comma bacillus." It 

 looks very like a caraway seed (Plate II., Fig. 5). 



In the carbol fuchsin specimen vast numbers of these curved 

 rods will be seen ; probably few other organisms, if any, will be 

 present if the case is one of true cholera. Two or more rods 

 may often be found joined together with their concavities turned 



