EXAMINATION OF WATER AND AIR. 251 
(Fig. 37). The stem must be sealed while the bulb is 
still hot, or while a little water is being boiled in it, so 
that a partial vacuum may exist in the bulb, in bite 
that the water may be sucked up into it when the 
stem is broken. The inoculation of the media is now 
made directly, or water from the tube is emptied into a 
sterile bottle or test-tube, or the end of the Sternberg 
bulb is sealed by heat. When water is to be obtained 
from greater depths or from beneath the surface of 
wells, more complicated forms of apparatus are neces- 
sary. A good example is the one devised by Abbott, 
Fig. 38. 
Fiask for counting colonies of bacteria. 
and made for him by Charles Lentz & Sons, of Phila- 
delphia. It consists of a metal framework in which is 
encased a bottle provided with a ground-glass stopper. 
To the stopper a spring clamp is attached, and this in 
turn is operated by a string, so that when the weighted 
apparatus is allowed to sink into the stream the stopper 
may be removed at any depth desired by simply pulling 
on the string. When the bottle is full the stopper is 
allowed to spring back into position by releasing the 
spring. Before removing the water the neck of the 
bottle should be sterilized by pouring a little of a 5 
