BLOOD-SERUM. 



93 



tube, or into small sterilized flasks of about 100 c.c. 

 capacity. It is then to be sterilized by the intermittent 

 method at low temperatures, viz., for one hour on each 

 of five consecutive days at a temperature of 68-70 C. 

 During the intervening days it is to be kept at the room 

 temperature to permit of the development of any spores 

 that maybe present into their vegetative forms, in which 

 condition they are killed by an hour's exposure to the 

 temperature of 70 C. 



At the end of this time the serum in the tubes may 



FIG. 16. 



Chamber for sterilizing and solidifying blood-serum. (Kocn.) 



either be retained as fluid serum or solidified at between 

 76-80 C. In solidifying the serum the tubes should 

 be placed in an inclined position so that as great a 

 surface as possible may be given to the serum. The 

 process of solidification requires constant attention if 

 good results are to be obtained, i. e., if a translucent, 

 solid medium is to result. If the old, small form of 

 apparatus be employed (Fig. 16), then the solidification 



OF THE 

 UNIVERSITY 





