BACTERIAL POISONS. 



195 



drawn from the animal; and the higher the temperature to 

 which the serum is exposed the more rapid the loss of potency. 

 It may remain potent for several days or for even a week or 

 more in the refrigerator, but if kept at body temperature 

 it generally loses all bactericidal properties in three or four 

 hours. Heating at 55° or 56° C. for ten or fifteen minutes also 

 robs the serum of its bactericidal power, or rather this treat- 

 ment of immune serum suspends its bactericidal power, which 

 is restored by the addition of a small amount of fresh serum. 

 This suspension of bactericidal power by heating at 55° or 

 56° C. is called inactivating the serum. Inactivated serum 

 to which fresh serum is added, and which has had its bacterio- 

 lytic properties restored in this way, is termed reactivated 

 serum. There are probably many circumstances which in- 

 fluence the bacteriolytic property of the serum. The chemi- 

 cal reaction of the serum has been found to influence the bac- 

 tericidal power, and doubtless there are other as yet obscure 

 circumstances which raise or lower this power of the serum. 

 The nature of bacteriolysins will be found discussed at some 

 length below, and it would not seem at all improbable that 

 there may be more of these at one time than at another present 

 in the blood-serum. Indeed, the production of bacteriolysis 

 in serum of the living animal seems to be easily influenced one 

 way or another, and it would not be unreasonable to regard 

 them as var3'ing from time to time under even slightly chang- 

 ing conditions of the body. 



Trommsdorf* noticed that human sera derived from normal 

 individuals as well as from those suffering from various dis- 

 eases vary greatly in bacteriolytic power. Pettersonf found 

 the same thing with chickens. 



*Richard Trommsdorf. Ueberden Alexingchaltnovmaler und pathologischer 

 mauschlicher Blutsera. CentralU. j. Bakt., etc. abt j.. Orig. Bd. 32, No 6, 

 pp. 436-449. 1902. 



tj. Morgenroth and H. Sachs. Ueber die Comp'etierbarkeit der ambocep- 

 toren. Berl. klin. Woch. Jahrg. 39, No. 27, pp. 631-633. 



