424 
D. J. MANGAN. 
In case the patient has not sufficient vitality to react, the im¬ 
munizing substances are not produced and the treatment fails; 
therefore, the earlier in the disease they are given the better will 
be the results. They should not be left as a last resort when the 
individual’s vitality is exhausted. 
In certain localized infections the body absorbs but little of the 
products of bacterial growths or antigens. Therefore, the amount 
of antigen absorbed being small, the amount of active immunity 
produced is slight. That is, little of the specific opsonins are 
formed, and those normally present are, to a large extent, used 
up so that the opsonic index is low and the disease tends to be¬ 
come chronic, or the part infected may be so badly damaged by 
the severity of the infection that the surrounding tissues are un¬ 
able to react and form the necessary opsonins. In this case the 
inoculation of the corresponding* bacterial antigen into a part 
distant from the site of infection where the tissues are injured is 
followed by an abundant elaboration of the specific opsonins 
which are delivered to the blood current, are taken to the in¬ 
fected part and reinforce the infected tissues in their fight against 
the invading 'bacteria. Again, the whole system may be over¬ 
whelmed by general bacterial infection so that the specific op¬ 
sonins formed and those normally present are rapidly used up. 
Hence the opsonic index is very low and the body is helpless to 
resist the infection. Here it has been proved in many cases in 
human medicine that the subcutaneous injection of carefully 
graded doses of the corresponding bacterial antigen can increase 
the specific opsonins. For it is the connective tissues and par¬ 
ticularly the loose cellular subcutaneous connective tissues that 
are, as a rule, the most active in the production on the anti bodies. 
Bacterial antigens should never be given intravenously , for 
there they would never increase opsonins. When injected into 
the body the proper place is in the above described tissues; distant 
from the focus of the disease and uninjured, they are better able to 
respond to the stimulus. 
Dr. Charles H. Duncan, of this city, has demonstrated that 
the administration of the crude autogenous pus per os will stimu- 
