204 APPLIED BACTERIOLOGY 



Practical Disinfection. — The saliva and discharges of the 

 nose and mouth should be regarded as virulently infectious, 

 and should, as far as possible, be received into rags and 

 burned before they have a chance to become dry ; the 

 excreta also should be disinfected. Any polluted linen that 

 cannot be conveniently burned should be soaked for one 

 hour in a solution of mercuric chloride (1 in 500) or 

 in bleaching-powder solution (6 ounces to the gallon), 

 and then well rinsed in fresh water before going to the 

 wash. 



All clothes, sheets, blankets, etc., should of course be 

 thoroughly disinfected in a steam disinfector. 



CHOLERA. 



Discovery and morphology of the organisra — Growth on media — Dis- 

 tinction from the Fiakler-Prior bacillus — Bacteriological diagnosis of 

 cholera — Indol reaction — Pathogenic effects on animals — Variations 

 in organisms — Occurrence and distribution — Transmission of the 

 disease — Methods of conveyance— Conditions of growth — Patho- 

 genesis— Specificity of organism — HaffMne's vaccine treatment. 



The Spirillum cholercn Asiaticce, the organism producing 

 true Asiatic cholera, is generally known as Koch's ' comma ' 

 bacillus. This organism was discovered by Koch in 1884, 

 in the excreta of persons suffering from cholera. The 

 researches of Koch in Egypt and India during 1884 showed 

 that this spirillum is constantly present in the contents of 

 the intestine of cholera patients, but is not found in the 

 healthy subject. Koch's 'comma' bacillus does not form 

 spores ; it is killed by drying ; its thermal death-point is 

 about 50° C, and it is very rapidly killed by sunlight. 



Method of Staining. — The cholera spirillum stains best 

 with an aqueous solution of fuchsine or gentian violet. It 

 is not stained by Gram's method. 



