MCCLYMONDS ON GERMS IN DRINKING WATER. 101 



water from tlio lierlin canals, obtained from the bodies of animals dving 

 from the inoculation, the bacillus of mouse septicemia, the short canal 

 bacillus and the capsulated bacillus. 



Koch's discovery of the spirillum of Asiatic cholera in 1884 and Mich- 

 ael's isolation of the bacillus of Eberth from a well in Grossburck, 1880, 

 cleai'ly established the causal relation of water to diseases in man. 



While nearly all the pathogenic bacteria have been found in water, 

 but three, the spirillum of Asiatic cholera, the bacillus of Eberth, and 

 the bacterium Coli Communis, have great practical importance. The 

 detection of the cholera and colon germs is a matter of comparative ease. 

 Unfortunately it is otherwise with the Eberth bacillus and its isolation 

 from drinking water is one of the most ditlicult problems with which the 

 bacteriologist lias to deal. 



During an outbreak of typhoid in Budapest, lasting for three months 

 and over, one thousand cases coming down, Fedor made hundreds of 

 examinations and succeeded in isolating the bacillus but five times. 



From two thousand examinations made by Kawalski in Vienna, but 

 five gave positive results. In the hundreds of examinations made in the 

 laboratory of hygiene, many of them with suspected waters, the bacillus 

 of Eberth has been found but once. 



This lack of success is in part explained by the following: 



(1) The slow growth of the bacillus in water, at the usual tempera- 

 ture, compared with ordinary water bacteria. 



(2) Its short life in water, especially water I'ich in non-toxicogenic 

 bacteria and other lower forms of vegetable and animal life. 



(3) Their unequal distribution. 



(4) The germicidal action of light, 



(5) The sedimentation of bacteria. 



(6.) The presence, usually in far greater numbers of Colon germs. 

 Many special methods have been devised to overcome some of these diffi- 

 culties. (1) Rodet added the water to bouillon and heated it from 

 45° to 45.5° C. for ^ to one hour. (2) Chantimesse and Widal em- 

 ployed a .25^ carbolic acid gelatin. (3) Virricent used five drops of a 

 five per cent solution of carbolic acid to 10 c. c. bouillon and incubated 

 at 42° for twenty-four hours. These methods are faulty in that thev 

 often destroy the Eberth bacillus. (4) The method of Parrietti has been 

 widely used and has given fair results. To tubes containing 10 c. c. 

 bouillon is added 1-10 2-10 3-10 c. c. of Parrietti solution. 



Carbolic acid 5 "-rammes. 



Hydrochloric acid C. I* 4 o-rammes. 



Distilled water 100 grammes. 



The tubes are incubated at 37° for twenty-four hours, then to each 

 tube is added ten drops of the suspected water, and the tubes again 

 incubated. If growth takes jjlace, indicated by the turbidity of the 

 bouillon, the bacillus of Eberth was said to be present. 



As now employed the bacillus must be obtained in pure cultures and 

 grown on various media. (5) Wasbutski examined larger quantities of 

 water by adding to it sufficient of a nutrient solution containing 10^ 

 each of glucose, peptone and sodium chloride to make a 1^ solution. 



