vative from albuminous bodies, having a close affinity to them. It
does not belong to the group of so-called toxalbumins, because it
bears high temperatures, and in the dialyzer goes easily and quickly
through the membrane. The proportion of the substance in the extract
to all appearance is very small. It is estimated at fractions of one
per cent., which, if correct, we should have to do with a matter whose
effects upon organisms attacked with tuberculosis go far beyond what
is known to us of the strongest drugs.

Regarding the manner in which the specific action of the remedy on
tuberculous tissue is to be represented, various hypotheses may
naturally be put forward. Without wishing to affirm that my view
affords the best explanation, I represent the process myself in the
following manner:

The tubercle bacilli produced when growing in living tissues, the same
as in artificial cultivations, contain substances which variously and
notably unfavorably influence living elements in their vicinity. Among
these is a substance which in a certain degree of concentration kills
or so alters living protoplasm that it passes into a condition that
Weigert describes as coagulation necrosis. In tissue thus become
necrotic the bacillus finds such unfavorable conditions of nourishment
that it can grow no more and sometimes dies.

This explains the remarkable phenomenon that in organs newly attacked
with tuberculosis, for instance in guinea pigs' spleen and liver,
which then are covered with gray nodules, numbers of bacilli are
found, whereas they are rare or wholly absent when the enormously
enlarged spleen consists almost entirely of whitish substance in a
condition of coagulation necrosis, such as is often found in cases of
natural death in tuberculous guinea pigs. The single bacillus cannot,
therefore, induce necrosis at a great distance, for as soon as
necrosis attains a certain extension the growth of the bacillus
subsides, and therewith the production of the necrotizing substance. A
kind of reciprocal compensation thus occurs, causing the vegetation of
isolated bacilli to remain so extraordinarily restricted, as, for
instance, in lupus and scrofulous glands.

In such cases the necrosis generally extends only to a part of the
cells, which then, with further growth, assume the peculiar form of
riesen zelle, or giant cells. Thus, in this interpretation, follow
first the explanation Weigert gives of the production of giant cells.