232 A MANUAL OF BACTERIOLOGY 



' it may, therefore, be readily understood how deadly 

 the cholera microbe may become if it once finds a 

 resting-place in milk.' 1 



Brunton, Lewis, and Cunningham, Klebs and 

 Cantani, and others, have all obtained indications 

 of a poison or ptomaine in cholera dejecta. Pouchet, 

 Brieger, and Yilliers have extracted several 

 ptomaines from cholera dejecta, as well as from 

 pure cultivations of the comma bacillus (Brieger). 



Dr. Lauder Brunton 2 says, c The symptoms occur- 

 ring in cholera are probably due to the action on 

 the tissues of a poison [or poisons] generated by 

 the microbe, and not of the microbe itself, just as 

 intoxication is due to the alcohol produced by the 

 yeast plant, and not to the action of the plant itself 

 on the nervous system and blood.' Besides the 

 ptomaines produced by the comma bacillus, this 

 microbe secretes a soluble enzyme. 3 



Cholera follows the course of rivers. Moisture 

 in the atmosphere and the soil is needed for its 

 distribution. Moist winds spread it, but the great 

 factor in the distribution of cholera, as already 

 stated, is human intercourse. Although human 

 intercourse is the chief factor in distributing this 



1 Hence milk adulterated with water from districts in which 

 there are persons suffering from cholora may be the means of 

 causing an epidemic of the disease. The same may be said of 

 typhoid fever. 



2 Disorders of Digestion (1888), p. 41 ; see also pp. 292 and 

 263 ; and Practitioner, 1884, et seq. 



3 See Dr. Brunton's paper in Proc. Roy. Soc. , vol. xlvi. p. 542 ; 

 and Dr. G. E. C. Wood's paper in Proc. Roy. Soc. , Edinburgh, 

 vol. xvii. p. 29. 



