TOXIC OR EXCITING INJFXTION 41 



The lymphatic glands become enlarged, there is ^ 

 some oedema, and the temperature rises to 1 40** F. 

 The general condition of the patient is such that there 

 can be no doubt as to the production of a general 

 toxaemia. 



Symptoms of serum sickness are produced some- 

 times — though not always — with quite a pecuUar 

 intensity in persons who have already been injected 

 with serum either recently or at some distant date. 

 In these patients the symptoms may appear very 

 rapidly after the injection. Even a minute or two 

 after inoculation one may witness true anaphylactic 

 shock such as is seen in the guinea-pig or rabbit, with 

 asphyxia and a condition resembling status lympha- 

 ticus (to say nothing of other symptoms already 

 described) which are displayed with an intensity that 

 is peculiarly impressive. Cases of sudden death 

 following reinjection have been recorded. It must be 

 added, however, that some of these cases are not to 

 be trusted, the part played by the serum not having 

 been properly established. 



Whatever the case may be, granting that serum 

 shock does not necessarily endanger human life, it is 

 none the less a mishap of sufficient gravity for the 

 practitioner to take the most serious account of it. 



Every time we make the statement that serum, 

 milk, and egg-albumen are toxic or lethal in such and 

 such a dose it must be understood that we by no 

 means intend to imply that they contain a substance 

 which is actually poisonous. There was a time when 

 this was believed to be the case, as we shall see ; but 

 this time has now gone by, and at the present day we 

 know that this toxicity is due to the union of two 

 substances — sensibiligen and sensibilisin — neither of 

 which taken separately is toxic at all. 



Why is this union toxic ? Is it because these two 

 substances, atoxic separately, by their combination 



