PNEUMOCOCCUS INFECTIONS 253 



dose of 1 c.c. against the minimal fatal dose, 5 c.c. would not neces- 

 sarily protect against five multiples of the fatal dose and so on. They 

 ascertained that there is a certain threshold of action beyond which 

 a given dose will protect against many multiples (up to a million) 

 of fatal doses, while below this point the activity of the serum 

 rapidly diminishes and may indeed be nil. 



In a concrete case the question naturally arises whether the type 

 of the infection corresponds to the strains with which the serum was 

 produced. To this end it is recommended to inject a mouse with a 

 small quantity (0.5 c.c.) of the patient's sputum to which one titer 

 dose of the serum has been added. If then the animal does not 

 succumb within the next twenty-four hours we may assume that the 

 serum is homologous to the type of the infection and would hence be 

 applicable. 



Mode of Action. As regards the mode of action of his antipneumo- 

 coccus serum Neufeld lays special stress upon its bacteriotropic 

 effect. It is possible, however, that it may have a certain bacterio- 

 lytic as well as antitoxic component as well. 



Dosage and Mode of Administration. As the absorption from the 

 subcutaneous tissue is notoriously slow the serum should be injected 

 intravenously whenever possible, or intramuscularly, if for any 

 reason (as in young children) the other route is excluded. The initial 

 dose for an adult is 40 to 50 c.c., and for children one-half of this 

 quantity, and may be repeated on the following day. If the patient 

 has been previously treated with horse serum it is recommended 

 to inject a small quantity (about 0.5 c.c.) a few hours before the 

 principal injection is given, the idea being to guard against anaphyl- 

 actic reactions by the production . of the antianaphylactic state. 

 Following the second injection no anaphylactic disturbances need 

 of course be anticipated (for the same reason) . Above all it is essen- 

 tial to inject as soon as the diagnosis has been made. 



Results. Regarding the results which may be obtained with 

 antipneumococcic sera prepared along the lines which have been 

 indicated by Neufeld and Handel, it would be premature to make any 

 definite statements. Suffice it to say that the treatment has no 

 appreciable influence upon the pathological-anatomical condition 

 of the lung, but that the general condition of the patient is apparently 

 improved and that an early crisis may be expected if the serum is 

 administered early. To what extent the death-rate will be affected 



