56 PRACTICAL BACTERIOLOGY 



CI. BLOOD SERUM 'QUICK METHOD. 1 



Processes 1 to 4, the same as 100, solid serum. 



5. Place the tubes in the serum sterilizer and heat at once to 90 

 or 95 C. for one hour or more. 



6. Place the tubes in an inclined position in the steam sterilizer 

 for one hour or more. The temperature must not run too high, other- 

 wise bubbles form in the serum. 



7. Place the tubes in the ordinary wire baskets, and sterilize as 

 usual for fifteen minutes on each of three successive days. 



Serum prepared according to this method is more opaque than 

 when prepared according to method 100, but answers all practical 

 purposes, saves time, and avoids imperfect sterilization, somewhat 

 common under the former method. 



FIG. 10. Koch's Apparatus for Congealing Blood Serum. 



CII. LOFFLEITS METHOD. 



Special Media for Cultivating the Bacillus Diphtherias. 



1. Take blood serum, 3 parts ; 1 per cent, grape sugar ; Bouillon 

 1 part. Mix well together, and fill into test-tubes. 



2. Solidify between 60 and 70 C. 



3. Sterilize for ten minutes in the steam sterilizer on each of three 

 consecutive days. 



Dr Nuttall has devised a bulb for the collection of blood serum. 

 It is a sterilizable vessel made of glass, by which 10 to 100 c.c. of 

 blood can be collected, and under proper precautions no contamina- 

 tion takes place. The method of procedure is as follows : 



Expose a femoral or carotid artery, and adjust two ligatures; 

 the one distant from the heart is tightened and the proximal one left 

 loose between the latter and the heart. The artery is clamped; a 

 small slit is now made in the wall of the artery, the point of the bulb 

 the sealed end of which has been broken off and rounded in the flame 

 is introduced, and the artery bound tightly around it with the loose 



