BACTERIAL ANALYSIS OF EGGS 465 
amount of the shell being removed without rupturing the membrane 
below. When this is accomplished the latter should be broken with a 
hot platinum spatula and with a sterile pipette 0.5 c.c. of the white of 
the egg quickly removed and placed in the necessary Petri dishes for 
cultures. The remaining egg white is then decanted, leaving the un- 
broken yolk in the shell. With another sterile pipette, the yolk sac 
is ruptured and suitable portions of its contents removed for study. 
While this procedure guards against contamination, the breaking up of 
the respective layers of the egg when out of this shell is difficult and 
sometimes the inability to do so interferes seriously with the obtaining 
of quantitative results. With the eggs which have been in cold storage 
for considerable periods a separation of the whites and the yolks is not 
possible. 
Bushnell and Mauer’s Method. The egg should be cleaned with 
brush and soap and immersed for ten minutes in a 1 to 500 solution of 
corrosive sublimate. It is transferred with sterile crucible forceps to a 
small conical graduate, acute pole uppermost. The corrosive subli- 
mate is removed and the egg dried by washing it first with alcohol 
and then with ether. The acute pole is scorched to kill spores, etc., 
that might remain. The egg is then immediately removed from the 
graduate by the operator’s holding it by the blunt pole, turning the 
acute pole down. The hands of the operator should have been thor- 
oughly greased with vaseline to avoid contamination of the flasks by 
bacteria which might drop off the hands while handling the eggs. 
With sharp, stout forceps, which have been sterilized in the flame, a 
hole about } cm. in diameter is made into the acute pole. Holding the 
ege with the acute end down, and making the stab from below prevents 
contamination from above. The shell around the hole is famed briskly 
and the egg is put with the acute pole upon the neck of a tall 300 c.c. 
Erlenmeyer flask containing 100 c.c. of sterile bouillon. The blunt 
end of the egg is now heated with a Bunsen flame, while a close watch is 
kept on the hole. The heating expands the air in the air space and 
this expels the contents of the egg. As soon as about half of the albu- 
men has run into the flask the heating is interrupted. The cotton plug 
is quickly removed from a sterile flask, the neck of the flask is flamed 
and the egg is transferred from the first to the second flask. Some- 
times it is necessary to invert the egg, as soon as the heating is discon- 
tinued, to prevent all of the albumin from running into the first flask. 
In this case it often happens that a little of the egg content runs down 
the outside of the shell, where it may become contaminated. To prevent 
such material from getting into the next flask, it is cemented to the 
