42 BACTERIOLOGICAL DIAGNOSIS. 
in the collection of specimens. Suppose, for’ instance, 
we wish to take some blood from a heart at a post- 
mortem examination for investigation at a distance. 
A point on the surface of the heart is first seared with 
a hot iron to destroy any germs which might be present, 
and the end of the pipette (still sealed) is thrust through 
into one of the cavities. It is then broken off by. dex- 
terous pressure against the heart-wall, and the: pipette 
will fill slowly with the blood. Another. method is to 
break off the tip of the pipette and to warm the bulb 
before making the puncture. The fluid will rise as the 
bulb cools; or both ends may be broken up and the fluid 
drawn into the bulb by gentle suction. 
Under any circumstances both ends of the pipette 
must be sealed up in a flame (the flame of a wax match 
will answer at a pinch) and the tube labelled. 
Another variety of pipette which is much used for the’ 
transmission of blood, for the purpose of testing the 
serum reaction for typhoid fever, is drawn out to a 
point at one end only, the other being left wide and 
separated from the bulb bya constriction (fig. 12 8). 
The open end should be loosely plugged with cotton- 
wool, and servés as a mouthpiece. The manufacture of 
these pipettes presents a little difficulty, but a small 
amount of practice will enable the practitioner to turn 
out a perfectly serviceable one on occasion. These 
pipettes are not so suitable as the others for the trans- 
mission of fluids for cultural examination or injection 
into animals. 
