CHARLES H. HIGGINS. 
2SS 
Killed cultures of bacteria, now known as bacterial vaccines 
have occupied a very important place among biological products 
for many years. None of these have received greater attention 
than that known as Haffkine's prophylactic consisting of the 
killed cultures of bubonic plague. The bacterial vaccine receiv¬ 
ing the most attention at the present time is the anti-typhoid 
vaccine, the efficacy of which as a prophylactic is well established 
from the numerous statistics available. 
r With the further development of bacterial vaccines we have, 
from a bacteriological standpoint, an extensive field opened be¬ 
fore us. These products require great skill in their preparation 
if they are autogenous in character and properly standardized. 
In a large measure their success depends, as with other products, 
upon the individual skill of the producer. All who are trained 
in the art and science of medicine do not make good clinicians, 
nor do they become equally proficient in the various specialties. 
Likewise, all pathologists do not acquire an equal proficiency in 
the preparation of these vaccines. The results are largely de¬ 
pendent on individual idiosyncrasies and judgment. The com¬ 
bined or polyvalent vaccines appear to be the most promising 
and will undoubtedly be the ones receiving the most general 
use. They have the advantage of being prepared from several 
strains of the same organism and are intended for use in those 
conditions where the infecting agent is similar to the types from 
which thev are manufactured. 
With respect to the necessary facilities required for the pre¬ 
paration of biological products, I will add but a few words. The 
buildings need not be expensive nor elaborately equipped. They 
should be spacious, well lighted, well ventilated and provide 
plenty of room for the laboratory workers and the animals re¬ 
quired in the conduct of the work. The details must be con¬ 
sidered individually in each instance, according to the work to 
be undertaken. All laboratory workers have a certain pride in 
their surroundings .and it is to be expected,, considering the 
risks constantly taken while working with large cultures of the 
most virulent infectious agents in the preparation of biological 
