EMERY'S METHOD 



779 



and the serum is pipetted off. Some blood is collected in citrate 

 solution, centrifuged, and the deposited corpuscles are washed 

 two or three times with saline. Equal volumes of the serum 

 and corpuscles are mixed. Nine parts of this reconstituted 

 blood are mixed with one part of an eighteen-hour old broth 

 culture of the Strep, fcecalis, which is chosen as the test-organism, 

 though other organisms may be substituted. One volume of this 

 infected blood is then taken in a Wright's pipette, having a unit 

 mark about 2 in. from the end, and one volume of the antiseptic 

 solution, the two are well mixed and then half the total is sucked 

 up into the same pipette and the other half into a second pipette. 

 The two pipettes are sealed at the point in the flame and incubated 

 at 37 C. in an opsonic incubator or in a water-bath. At the end 

 of fifteen minutes one pipette is taken, the point is sterilised in 

 the flame and broken off and a loopful of the mixture is spread 

 over as wide an area as possible on the surface of an agar plate. 

 The second pipette is treated in the same way at the end of an 

 hour. The plates are incubated for twenty-four hours, and the 

 results noted. In this way the germicidal value of the disinfectant 

 is ascertained after it has acted for periods of fifteen and sixty 

 minutes. 



The following is a table of the results obtained by Emery by 

 this method : 



* Causes diminution in number of organisms but does not kill all of them. 



On the Kideal- Walker method, etc., see Approved Technique 

 of the Eideal-Walker Test, Kideal and Walker (Lewis, 1921) ; 



