HUNTOON AND HUTCHISON 929 



anti-pneumococcic serum is found in the method of Felton, in which o.oi cc. of a 

 culture kiUing in o.oooooooi cc. is taken as a standard, and varying dilutions of the 

 serum are tested against that standard. There are both theoretical and practical 

 reasons for a preference for this method. In the testing of antibacterial sera by the 

 protection method against living virulent organisms, a third component of the reac- 

 tion must be furnished by the animal. Where o.oi cc. of culture is employed, one 

 may be certain that there is an excess of this component present, and the results ob- 

 tained by this method are much more sharp cut and regular than by the standard 

 method. 



The presence of agglutinins is no indication of the protective value of the serum, 

 and is useful only where diagnostic sera are desired. 



THE VALUE OF ANTI-PNEUMOCOCCIC SERA 



The accumulated reports have been critically examined by Locke,' with a view 

 to estimating more accurately the clinical value of this mode of treatment. Limiting 

 his analysis to the type I serum, which is admittedly the most potent, Locke states 

 that "a final estimate of the value of this serum in Type I lobar pneumonia, based 



on the figures thus far published, is impossible Granted that the serum is 



given every eight hours and in sufficient doses, the most vital consideration is un- 

 questionably the stage of the disease when serum injections are begun." While it is 

 impossible to foretell the results of serum therapy in individual cases, yet there is some 

 reason to believe that anti-pneumococcic serum of high potency, properly adminis- 

 tered in adequate dosage, is of definite value in the treatment of type I pneumonia. 



CONCENTRATED ANTI-PNEUMOCOCCIC SERA 



Probably the first instance of the successful concentration of antibacterial im- 

 mune bodies from sera is recorded in the announcement by Izar and Caruso.^ In 192 1 

 they concentrated antibodies by dilution of the serum with double distilled water. 

 In 1924 Felton^ announced success with a practically identical method. With close 

 attention to the hydrogen-ion concentration and the proportion of distilled water, a 

 precipitate was obtained, apparently of euglobulins, and roughly proportionate in 

 volume to the potency of the sera. 



Felton's serum is therefore essentially a concentrated anti-pneumococcic serum, 

 and it contains probably about 1.5-2.5 per cent serum proteins. Banzhaf^ has also 

 prepared a concentrated serum by a modification of Felton's method, 



ANTIBODY SOLUTION 



As early as December, 1919,^ one of us (F, M, H.) announced success in preparing 

 a solution of pneumococcus protective antibodies, "approximating in antibody con- 

 tent the best immune sera and containing so low a serum protein content that 5 cc. 



'Locke, E. A.: J.A.M.A., 80, 1507. May 26, 1923. 



^ Izar, G., and Caruso, G.: Riforma med., 38, 145. Feb. 13, 1922. 



i Felton, L. D.: Boston M. b° S. J., 190, 819. May 15, 1924. 



4Banzhaf, E. J.: Weekly Bull. New York Dept. of Health, 16, 17. Jan. 29, 1927. 



sHuntoon, F. M.: Tr. Philadelphia Path. Soc. (N.S.), 22, 75. 1920. 



