Kirchner — Bacteriological Examination of River Water. 269 
adjusted around the stopper, the apparatus may be lowered 
into the water. By pulling the rod the stopper will be raised 
and the water will enter the bottle. On releasing the hold on 
the rod, the spring returns the stopper into the neck of the 
bottle. The stopper of the tube which contains the ther- 
mometer having also been removed, the apparatus may be 
withdrawn from the water. . 
The apparatus has the advantage that it may be operated 
with one hand. It is firm and simple of construction, and, 
although subjected to rough usage, has given entire satisfac- 
tion. A similar but larger apparatus has been used for 
taking samples for chemical analysis. 
The bottle for the collection of samples should have a well- 
fitting stopper, and the top having been wrapped with lead- 
foil and a cloth, the bottle should be sterilized. After 
collecting, the lead-foil and cloth should be replaced, and the 
bottle should be placed in a clean can and packed in ice. 
Each sample should be properly labeled, and should bear the 
date, location, temperature of air and of water, name of col- 
lector, and other special data. 
Transportation of Samples. —'The samples having been 
collected, they should be examined at once, or, if this is not 
possible, they should be transported to the laboratory with 
the greatest possible dispatch. Itis essential that the samples 
be kept not only ‘‘cold,’’ but their temperature while in 
transit should be kept at or near the freezing-point by packing 
them in ice. It is well-known that bacteria in samples of 
water generally multiply and reach enormous numbers under 
favorable conditions of growth, but in order to obtain definite 
information on this point, I made a number of tests which 
illustrate of how great importance the factors of time and tem- 
perature are in arriving at the actual conditions of the water. 
Samples arriving at the laboratory were plated immediately 
for a quantitative determination and were then placed in that 
compartment of a household refrigerator where the ice is 
kept. The samples were replated on the next day after an 
interval of nineteen to twenty-four hours. Sixty-six tests 
were made in this manner, but for illustration it will be 
necessary only to give a portion of the results. (Table I.) 
