246 SCIENCE FROM AN EASY CHAIR 



cholera-bacillusj which had probably lodged in his intestine 

 some weeks previously at the commencement of the out- 

 break of the disease in Egypt. Though living in him the 

 cholera-bacilli had not found a favourable field of growth. 

 This man in handling the cold broth, the cloth used to 

 rub the spoon with which it was stirred, or the basin itself, 

 had, it was found by making the actual experiment, been 

 able to transfer the minute bacillus to the cold broth, a 

 most favourable and nourishing medium for its growth, 

 and so his isolated carefully guarded employer received 

 an abundant crop of the bacilli and developed a fatal 

 attack of cholera. Had the lady taken the broth hot, 

 there would have been no living cholera-bacillus in it, and 

 if she had thus guarded herself in regard to all food, by 

 the use of heat and great cleanliness, she would have 

 escaped infection. 



The most interesting development of knowledge and 

 speculation with regard to the microbes which infest the 

 human intestine and other regions of the human body 

 is (as I mentioned above) connected with the fact that one 

 kind or species of microbe has the power of favouring the 

 growth of another, if present alongside of it, and that 

 another kind has the power of checking or antagonising 

 its growth. Thus common putrefactive microbes of river 

 water are hostile to the cholera-bacillus and to the typhoid- 

 bacillus. Those disease-producing bacilli live longest and 

 best in very pure water ! Thus, too, it is found that the 

 microbe of sour milk the lactic-bacillus is antagonistic 

 to the common putrefactive microbe of the intestinal con- 

 tents the well-known bacillus coli. In virtue of the acid 

 which it produces, the microbe of sour milk arrests the ex- 

 cessive growth and activity of the putrefactive bacillus coli. 

 Hence the utility of sour milk in many cases of intestinal 

 trouble. We contain within us a microbian flora of such 

 variety and abundance of kinds and so nicely balanced 



