76 ROCHESTER ACADEMY OF SCIENCE. [June 23, 
tion of this moist portion showed an abundant growth of the large bacilli 
characteristic of the bacillus of typhoid fever. 
This culture was put through all the forms of nutrient medium, and 
staining that are necessary for its identifiction, and showed the characteristica 
reactions in them all. 
A summary of the work done npon these last four samples shows that : 
Water AA, contained 36,000 colonies to the c.c., with a few liquefying 
colonies, and apparently large numbers of the same organism. 
Water BB, 6,000 colonies to the c. c., no liquefying and most of the coionies, 
appearing the same. 
Water FF, 60,000 colonies to the c. c., no liquefying, and very evidently 
enormous numbers of the same organism. 
Water DD, 165 colonies to the c. c., about one-half the colonies liquefy- 
ing, and several kinds of micro-organisms, among them the 
Koch-Eberth Bacillus of Typhoid Fever. 
From the face of the results alone, it would be proper to condemn the waters 
numbered 1, 2, 3, 8, 9, 15, AA, BB, FF, doing this because they all contain a greater 
number of bacteria to the cubic centimetre than is in accordance with a good standard. 
But the chemical analysis does not bear out this assertion, nor does the consideration of 
the conditions found. In general it is true that, water analysed by bacteriological 
methods and which contains a large amount of bacteria is not to be condemned if there 
are many of the same kind of organisms present, because in such a case all that we are 
absolutely justified in doing is to say that that especial organism has found a peculiarly 
favorable medium for its developement in this sample of water. Now this is just what 
has happened in the case of all the waters submitted for analysis, that there was found in 
all of them a marked similarity in the mass of the bacteria found in each specimen, and 
the excessive numbers found in some of them must be ascribed, in some degree at least, to 
the delay before the examination was begun, this delay being caused by the distance 
that the waters had to travel before being submitted to examination. 
The water marked ‘*‘DD” should not be condemned at all for the sumber of 
bacteria found, but for an entirely different reason, that the 4émds of bacteria are sp 
numerous among so small a number. The conclusion that I have reached, therefore, was 
that this water had been contaminated by sewer or other organic matter, and this before 
the chemical analysis had been made, and it will appear that the chemical analysis had 
led to the same conclusion. 
The excessive liquefaction of the gelatine plates spoken of, means that there were so 
many of that variety of bacteria—those possessing the power of liquefying gelatine— 
preseut in the original fluid that they destroyed any possibility of separating the other 
forms. The typhoid bacillus does not liquefy gelatine, and its presence may therefore be 
very easily concealed if there be many of the liquefying forms present. It is also 
destroyed with comparative ease by the presence of many other organisms, and that is 
the probable reason that we failed to find it in the water which should have been strongly 
suspected of its presence, from the clinical history of the cases occurring among the users 
of it. The importance to be attached to the presence of many liquefying bacteria, more 
