340 BACTERIOLOGY OF THE EYE 



Where the older treatment cannot be used or is inefficient, especially 

 in cases of great responsibility (single eye, etc.), serum can be used 

 as an assistance to other means. 



Its utility is therefore very limited. With more efficient methods, it 

 may perhaps be possible to further advance the use of sera in the 

 treatment of corneal infections. 1 



Quite recently 2 Eomer reported that he had given up the use of the 

 polyvalent serum, and that he was preparing a new serum which 

 would be issued by the Hoechst Seruminstitut ; this would not be 

 a polyvalent serum, but one prepared from strains pathogenic for 

 animals. 



This serum is not yet available, and when it does appear will require 

 to be tested with the greatest care and critically examined to see 

 whether it really is any better than the other sera available. Till it 

 is available for testing, it is better to postpone the account of the 

 properties which Homer ascribes to it. 



At present we can only form an opinion about the polyvalent serum 

 of Merck ; it is the only one which is on sale. Its advantages and 

 disadvantages have already been considered. 



1 Concerning the use of serum in the prevention of wound infections, cf. p. xx et seq. 



2 Heidelberg Congress, 1907. 



