Medical Officers of the Army of India.
49
explanation for the apparently anomalous course followed by different cases of
cholera—for the fact that cases which initially were extremely severe may show
no secondary symptoms, and that cases which initially were comparatively mild
may ultimately show them in the highest degree. If the initial symptoms be
due to the absorption of a poison of extrinsic origin, and the secondary ones to
the action of a poison developed within the intestinal tract in consequence
of the profound alteration in the nature of its contents following the action of
the primary disease, there is clearly no necessity why they should invariably
bear any definite relation to one another. Had the organisms which come to
prevail in the intestinal contents in their abnormal state invariably been of one
and the same nature, there would have been good reason for assuming that a
constant and definite relation should be' traceable ; but when we know that many
distinct organisms may come to the front, this is no longer the case, and, in place
of there being any ground for expecting a uniform sequence of events, there is
every reason for expecting that there should be a diverse one, such as we find
actually existing.
In the light of the epidemiological and experimental data which are now
on record, it would appear that there are good grounds for adopting a new
theory of the causation of cholera, or more correctly for adopting a modification
of that long ago so forcibly advocated by Professor von Pettenkofer. Accord-
ing to this we must recognise the action of two distinct factors on the produc-
tion of the phenomena which are present in most cases of the disease—of two
distinct poisons, one of which is manufactured in the environment and the other
within the intestinal tract. They need not, however, be invariably associated with
one another, as the development of the latter of them is dependent on the presence
of certain schizomycete organisms within the intestinal tract at the time when
the action of the poison of extrinsic origin gives rise to profound changes in
its contents. In cases where they are not present the phenomena of the disease
will be those of simple ptomaine-poisoning, and the result will be determined
practically by the dose of toxic material which was ingested. In cases where
such organisms are present, on the other hand, the outcome of the attack will be
essentially influenced by the capacity which they possess for manufacturing
poisonous products. The dose of the initial poison here ceases to be all
powerful in determining the course of the disease, and even very small doses of
it may indirectly lead to a fatal result so long as they are sufficient to give rise
to such changes in the intestinal fluids as to favour the multiplication of the
factors of the secondary one. The ingestion of the poison which gives rise to
the initial symptoms is not in any way necessarily accompanied by the inges-
tion of the factors of the poison which gives rise to the secondary ones, it
merely secures that should these be present they may encounter favourable
conditions for the exercise of their activity in manufacturing it. Just as the
primary poison cannot be manufactured in the outer world in the absence of
H