THE MULTIPLICATION OF MICRO-ORGANISMS 241 



A green fluorescent bacillus, obtained from seltzer- 

 water, remained stationary as regards numbers up to 

 the fourth day, after which, up to the ninth day, it 

 declined, and after fourteen days had died off. 



A yellow bacillus, also obtained from seltzer-water, 

 multiplied extensively, and was found in large num- 

 bers even after thirty-three days ; when examined after 

 seventy-seven days it was no longer demonstrable. 

 Hochstetter's experiments on the vitality of patho- 

 genic bacteria in seltzer-water are given in the various 

 tables, in the case of each organism investigated, in 

 Chapter VIII. 



Slater 1 has examined a number of different arti- 

 ficial aerated waters, and confirms the results of pre- 

 vious observers as regards the wide variations in the 

 number of micro-organisms present, ranging from three 

 up to 2,919 in 1 c.c. These waters were manufactured 

 from river or deep -well water as supplied to London, 

 also from private artesian wells, and were in some cases 

 filtered through animal or vegetable charcoal before 

 use, distilled and boiled water being also employed. 

 Slater states that the bacterial purity of the original 

 water is undoubtedly frequently effaced by the con- 

 taminations which occur in the process of manufacture. 

 This investigator also found that if the carbonic 

 anhydride were allowed to escape, the water being 

 subsequently kept under sterile conditions, a rapid 

 multiplication of the bacteria took place, indicating 

 that this gas exercises a retarding action on the vitality 

 of the bacteria present, thus : A sample of aerated 

 water contained, before loss of C0 2 , 374 microbes in 

 1 c.c. ; when examined seven days after it had lost 



1 'Investigation of Artificial Mineral Waters,' Journal of Pathology 

 and Bacteriology, vol. i., 1893, p. 468. 



E 



