134 PHARMACEUTICAL BACTERIOLOGY. 



C. The second precipitation product is treated with a saturated salt 

 solution which dissolves the antitoxin globulins. The solution is then 

 filtered. 



D. To the filtered solution 2.5 per cent, of acetic acid is added which 

 again precipitates the globulins on the filter paper where it is partially dried 

 by means of filter paper and towels pressed upon the mass. 



E. The partially dried material is placed in a dialyzing bag and suspended 

 in a water current, for several days. This removed the salts by osmotic 

 action and at the same time the globulins enter into solution within the bag. 



F. A preservative is added to the liquid and which is then passed through 

 a Berkefeld filter. Some physiologic salt solution is also added. This is 

 the final product. 



G. .After being tested bacteriologically to make sure that it is not con- 

 taminated, it is standardized as described under diphtheric serum. 



The above process removes the following non-active substances: serum 

 albumins, lecithin, cholesterin, traces of bile salts and acids, blood salts 

 and the non-antitoxic globulins. The dosage of the concentrated antitoxin 

 is less than that of the non-concentrated serum and it keeps longer. For 

 the manufacture of the concentrated diphtheria antitoxin the returned 

 serum is generally employed, that is serum which has exceeded the time 

 limit of use. 



5. Antitetanic Serum. 



This is prepared similarly to antidiphtheric serum. The tetanus bacilli 

 are grown in bouillon, in the absence of oxygen, since tetanus germs are 

 anaerobic. The growth is then killed, filtered out and the clear toxic, germ- 

 free bouillon filtrate is utilized in the immunization of the horse. Small doses, 

 usually mixed with some antitetanic serum, are administered at first and 

 gradually increasing the amount as the horse can stand it until large quantities 

 are given, even as much as 700 or 800 c.c. After some months the horse is 

 bled in the same manner as for antidiphtheric serum, the serum is separated 

 and bacteriologically tested in the same way. 



The unit of tetanus antitoxin is that quantity of antitetanic serum which 

 is necessary to completely neutralize 1000 fatal doses of tetanus toxin for a 

 25o-gram guinea-pig. 



Antitetanic serum has not been a marked success as a curative agent. Its 

 greatest usefulness appears to be as a prophylactic, for which purpose it 

 should be given early, as soon as the injury (cut, gunshot wound, abrasion) 

 has occurred. 



The following are the more important antibacterial sera. A fuller 

 description of the processes of manufacture is omitted as that is a matter of 



