io IMMUNE SERA 



filled with creamy pus is formed within four days; 

 there is a widespread undermining of the skin. 

 The same quantity of turpentine injected into the 

 pleural cavity causes a serofibrinous inflammation 

 which undergoes resolution so that the pleural 

 cavity is restored to its normal condition after about 

 ten days; there is no destruction of tissue and a 

 scar is not formed. In the subcutaneous tissue 

 only a small amount of cedematous exudate can 

 accumulate; the undiluted irritant causes active 

 migration of leucocytes so that the antibody of the 

 exuded serum is soon overbalanced by the enzyme 

 set free by disintegrated pus cells. In the pleural 

 cavity, on the contrary, a large quantity of serum 

 quickly accumulates and the exudate is sero- 

 fibrinous instead of purulent; the antienzyme it 

 contains is capable of holding in check the enzyme 

 of the accumulated leucocytes. If a bit of the 

 fibrinous exudate is suspended in the exuded 

 serum, it is preserved intact. Nevertheless, by 

 repeated injection of turpentine at short intervals 

 into the pleural cavity, accumulation of leucocytes 

 can be prolonged so that finally a condition is 

 produced in which antienzyme can no longer 

 restrain the enzyme. The softened fibrin of such 

 an exudate quickly disintegrates in the serum of 

 the exudate. These observations, as Opie points 

 out, help to explain how the typhoid bacillus pro- 

 duces abscesses in certain situations such as the 



