Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1882-05-11
THE ruBERoLE PARASITE.
A New Theory of Consumption
Professor John Tyadall's
LuminOus Account OF
Dr. KOeh's Investiga-
tiOns.
London Times

terccbCu- buhb VI CApOlAAuOuOdl phgoA-
oIogy-and may, therefore, be per-
mitted to give some account Ofitin the
Times. The address, q copy Of which
has been courteously sent to me by Its
author, is entitled THE Etiology of
Tubercular Disease" Koch first made
himself known by the penetration,
skill and thoroughness of his re-
searches on the contagium Of splenic
fever. By process of incubation and
infection he traced this terrible para
site through all its stages Of develop
ment and through its various modes of
action. THIS mastery investigation
caused the young physician to be trans
ferred from modest country practice,
in the neighborhood of Breslau, to the
post Of Government Advisor in the
Imperial Health Department Of Der
lin.
From this department has lately
issued a most important series Of in
vestigations on the etiology Of disor
ders. Koch's last inquiry deals with
a disease which, in point of mortality,
stands at the head of them all. If, he
says, the seriousness of maladv be
measured by the number of its victims
then the most dreaded pests which
have hitherto rayaged the world
plaques and cholera lncluded-must
stand far behind the one now under
consideration. Koch makes the start
ling statement that one seventh Of the
deaths of the human race
are due to tubercular dis
ease, while fully one-third
Of those who die in active middle age
are carried IF by the same cause.
Prior to Koch it had been placed be-
yond doubt that the disease was COM
municable, and the aim Of the Berlin
physician has been to determine the
precise character Of contagion which
previous experiments on incubation
and inhalation had proved to be capa
Bile of indefinite transfer and repro
duction. He subjected the diseased
organs Of great number Of men and
animals to microscopic examination,
and found, in all cases, the tubercles
infested with a minute, rod shaped
parasite, which, by means OF a
special dye, he differentiated from the
surrounding tissue. 1t was, he says,
in the highest degree impressive to OBJ
serve in the center of the tubercle cell
the minute organism which had created
it. Transferring directls. by incubation,
the tuberculous matter from diseased
animals to healthy ones, he in every
instance reproduced the disease. To
meet the objection that it was not the
parasite itself, but some virus in which
it was imbedded in the diseased organ,
that was the real contagium, he cult.
waited his bacilli arti6cially for long
periods of time and through many sug
gestive generations. With speck of
matter, for example, from tubercu-
lous human lung, he infected a sub
stance prepared, after much trial, by
himself, with a view of afording nu-
triment to the parasite. From this
new generation be took minute sam
pie and infected Herewith fresh nu-
tritive matter, thus producing another
brood. Generation after generation of
bacilli were developed In this way
without the intervention of the dis
ease. At the end of the process,
which sometimes embraced successive
civilizations extending over half a
year, the purified bacilli we're intro
duced into the circulation Of healthy
animals of various kinds. In
every case incubation was followed
by the reproduction and spread of the
parasite and the generation of the
original disease.
Permit me to give further, though
still brief and sketchy, account Of
Koch's experiments. Of six guinea
pigs, all in good health, four were in
oculated with bacilli derived originally
from human lung, which in ifty-
four days had produced FIVE successive
generations. Two Of the six animals
were not infected. In every one Of
the infected cases the guinea pig
sickened and lost flesh. After thirty
two days one of them died, and after
thirty five days the remaining FIVE
we're killed and examined. In the
guinea-pig that died. and in the
three remaining injected enes, strongly
pronounced tuberculsr disease had set
in. Spleen, liver and lungs were
found filled with tubercles; while in
the two unaffected animals no trace
of the disease was observed. In o
second experiment, six out Of eight
guinea pigs were inoculated with cul
tivated baciAi, derived originally IRON
the tuberculous lung OF monkey
bred and rebred for ninety.fve days
until eight generations had been pro.
duced. Every one of these animals
was attacked, while the two unaffected
guinea pigs remained in perfectly
healthy state. Similar experiment.
were made with cats, rabbits, rats
mice, and other animals, and, without
exception, it was found that the in
lection Of the parasite into the ami
NAL system was followed by decided
and, in N ost cases, virulent tubercu
lar disease.
In the cases thus far mentioned, in
oculation had been effected in tn,
abdomen. The place Of inoculatiol
was aiterward changed to the aqueous
humor Of the eye. Three rabbits re
ceived each speck of bacillus-culturC
derived originally from human luu
affected with pneumonia. Eighty
nine days had been devoted to tb
culture Of the organism. The infecte
rabbits rapidly lost flesh, and afte
twenty-five days were killed and ex
amined. The lungs of every one Z
them were found charged with tuber
cles. OF three other rabbits, on
received an injection of pure bloc
serum in the aqueous humor of tn
eye, while the other two were infecte
in similar way with the same SERUM
LII. J.-.-oI -. N