54 
PRINCIPLES OF BACTERIOLOGY 
II, The Infection Proper—Bacterial Poisons 
When all of the above conditions have been complied 
with, we will have an infection, which may be either 
local or general. If only inflammation of a part or an 
abscess (pns accumulation) in a certain part results, 
we speak of this as a local infection; on the other hand 
from such a local infection—or without it—the bacteria 
may gain entrance to the lymph and blood vessels and 
be carried into the circulation and thus be distributed 
through the entire body—this is called “septicemia” 
(from Greek septikos, meaning putrid and aima, mean¬ 
ing blood) or (b}^ the laity) blood poisoning. If the bac¬ 
teria thus carried to other organs form abscesses there, 
we speak of this condition as “pyemia” (from Greek 
pion, meaning pus, and aima, meaning blood). 
Septicemia and pyemia are caused in a large majority 
of cases by streptococci and staphylococci. 
It is evident, however, that mere local injurious effects 
or blocking of the small blood vessels (capillaries, from 
Latin meaning hair-like) are not sufficient to account 
either for severe general effects following infection or 
for the fact that the same bacteria produce the same in¬ 
jury no matter where they lodge (within their special 
path of entrance, of course)—in other words it is evident 
that bacteria produce their effects not mechanically, but 
chemically, by means of the so-called bacterial poisons, 
which are called toxins (from Greek toxicon, meaning 
poison). 
Those toxins are of three kinds: 1. Exotoxins (“ex¬ 
ternal” poison) which are separable*' poisons, secreted 
by bacteria just as sweat is secreted by the sweat 
*1 believe the usual terms “soluble’' and “insoluble’’ had better be 
dismissed, as (in my experience, at least) they usually are a source 
of confusion to the pupil. “How do the insoluble poisons do any 
harm if they are insoluble?’’ is a favorite question. 
