Report on the Bacteriology of Water. 



213 



decomposition of those which die when first put into the water. 

 Braem has shown pretty clearly that in some cases, at any rate,* 

 distilled water kills anthrax and cholera bacilli, as well as Staphylo- 

 coccus pyogenes aureus, though not always rapidly. Thus cholera 

 lived for 24 hours, anthrax from 8 to 12 days, while the Staphylo- 

 coccus required 25 to 50 days for its elimination. 



Braem says that the typhoid bacilli were still active after 60 days 

 in distilled water, and were not eliminated till 188 days had 

 passed. 



In the present state of our knowledge such results can most reason- 

 ably be explained on one of the three following assumptions : — 

 (1) Either the distilled water was not pure (i.e., it was contaminated 

 in the still, or more probably by food materials carried in during in- 

 fection) ; or (2) the products of decomposition of the dead and dying- 

 bacteria during the sojourn in the water, afforded food materials 

 for the rest. Most probably both sources of error occur in 

 those cases where the increase is very marked and prolonged: of 

 course the products of decomposition of previously living bacteria 

 would only account for a smaller number than the original, i.e., the 

 usual case. Whilst (3) the possibility may be suggested, that the 

 progeny formed in the distilled water is of a degraded order, in which 

 the individuals have a smaller dry body weight than the original 

 forms introduced. 



Uf£elmann,t experimenting with the waters of Rostock, finds that 

 typhoid bacilli, at ordinary temperatures, can hold their own for from 

 several days to two weeks; and that Bacillus anthracis remained alive 

 for three months. Although cholera germs are much less resistant, 

 yet they, also, may be carried in such waters as are used for domestic 

 purposes. 



KarlinskiJ investigated the bacteria of five Innsbruck waters, and 

 then determined their normal behaviour at 8° C. : in all, the numbers 

 of Schizomycetes increased when the water was allowed to stand at 

 this temperature. He then infected these waters with the bacilli of 

 typhoid, cholera, and anthrax, and kept them also at 8° C, and found 

 that these all diminished rapidly in numbers in the struggle with 

 the increasing and eventually dominant water forms. Cholera could 

 not maintain itself for three days, typhoid not beyond six days, and 

 anthrax three days at the given temperature. It will be noticed that 

 this is a valuable confirmation of Kraus's results at lO'S C. 



* " Recherches sur les Phenomenes de Degenerescence des Bacteries Pathogenes 

 dans l'Eau Destillee" (Ziegler's ' Beitr. zur Pathol. Anat.,' vol. 7, H. 1). 



f "Trinkwasser und Inf ections-krankheiten " ('Wiener Medicinische Presse,' 

 1888, No. 37). 



X " Ueber das Verhalten einiger pathogener Bakterien im Trinkwasser" ('Arch, 

 f. Hyg.,' vol. 9, 1889, p. 113). 



