The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1882-05-05
III The Editor of The Dispatch:



OF very serious public import was delivered
by DIR. Koch before the Physiological So
ciety Of Berlin. 10 touches q question In
which we are all at present interested
that OF experimental physiology-aQd l
may therefore be permitted 10 glyeNome
account Of it in the Times.
The address, a copy of which has been
courteously sent to me by its author, is en-
titled "The Etiology OF Tubercular Dis
ease.v Koch first made himself known by
the penetration, skill, and thoroughness OF
his researches on the contagium OF splenic
fever. BY process Of incubation and in
lection he traced this terrible parasite
through all its stages OF development and
through its various modes OF action. This
mastery investigation caused the young
physician TO be transferred from a modest
country practice in the neighborhood Of
in the Imperial Health Department OF Ber-
lin.
From this department has lately issued q
most important series Of investigations on
the etiology OF .nfective disorders. Koch's
last inquiry deals with disease which, in
point of mortality, stands at the head OF
them all. III, he says, the seriousness of
malady be measured by the number of its vic
Tins, then the most dreaded pests which
have hitherto rayaged the world-plague
and cholera included-must stand lar be-
hind the one now under consideration.
Koch makes the startling statement that one
seventh of the deaths OF the human race are
due to tubercular disease, while fully one
third OF those who die in active middle
age are carried off by the same cause.
Prior TO Koch it had been placed beyond
doubt that the disease was communicable
and the aim Of the Berlin physician has
been to determine the precise character of
the contagium which previous experiments
on incubation and inhalation had proved
20 be capable of indefinite transfer and re.
production. He subjected the diseased or
gans Of a great number Of men and ami
mails TO microscopic examination, and
found, in all cases, the tubercles infect
ed with minute, rod-shaped para
site, which, 10y means of a special
dye, he differentiated from the surround
ing tissue. 1t was, he says, in the highest
degree impressive to observe in the centre
of the tubercle cell the minute organism
which had createdit. Transferring direct
Iy, 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 i'm the diseased organ, that
was the real contagium, he cultivated his
bdcili artiticially for long periods OF time
and through many successive generations.
With a speck OF matter, for example,
from tuberculous human lung, he
infected a substance prepared, after
much trial, by himself. with the view
Of affording nutriment TO the parasite.
Here he permitted il TO grow and
multiply. From this new generation he
took minute sample and infected there
with fresh nutritiye matter, thus producing
another brood. Generation after genera
ton of JociW were developed in this way
without the intervention of disease. At
the end of the process, which sometimes
embraced successive civilizations extend
ing over half year. the purified bdciM
were introduced into the circulation of
healthy animals of various kinds. In every
case incubation was followed by the repro
duction 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 eX-
periments. OF six guinea-pigs, all in good
health, four were inoculated with bdciM
derived originally from a human lung.
which, in fifty-four days, had produced five
successive generations. Two OF the six
animals were not infected. In every one
OF the infected cases the gulnea-pig sick
<ned and lost flesh. After thirty-two days
one Of them died, and after thirty-ive DAYS
the remaining five were killed and exam
ined. In the gIlinea-pig that died, and in
the three remaining infected ones, strongly
pronounced tubercular disease had set
in. spleen, liver, and lungs were found
filed with tubercles; while in the two
unlnfected animals no trace of the disease
was observed. In a second experiment
six out of eight gninea-pigs were inocu-
lated with cultivated b0ciii, derived orig
inaIly from the tuberculous hung of
monkey, bred and rebred for ninety-fye
days, until eight generations had been
produced. Every one of these animals
was attacked, while the two uninfected
guinea-pigs remained perfectly healthy.
Similar experiments were made with eats,
rabbits, rats, mice, and other animals, and,
without exception, ii was found that the
Injection OF the parasite into the animal
system was followed by decided and, in
most cases, virulent tubercular disease.
In the cases thus far mentioned inocula-
fion had been effected in the abdomen.
The place OF incubation was afterwards
changed 10 the aqueous h,imor OF the eye.
Three rabbits received each speck OF
6acilips culture, derived originally from
human lung affected with pneumonia.
Eighty-niDe DAYS had been devoted TO the
culture OF the organism. The infected
rabbits rapidly lost flesh, and after
twenty-five days were killed and exam |
ined. The lungs OF every one Of
them were found charged with tuberces.
OF three other rabbits, one received an ]
injection OF pure blood-scrum in the aque-
Gus bllmOr of the eve. while the other two
were infected in similar way, with the
same serum, containing bacini, derived
originally from diseased lung, and SUBJ
Jected 10 ninety-onc days cultivation.
After twenty-eight days the rabbits were
killed. The one which had received an |
Injection Of pure serum was found per- |
fectiy healthy, while the lungs Of the two |
Others were found oyerspread with tuber- |
cles.
Other experiments are recorded In THIS |
admirable essay, from which the weightiest |
practical conclusions may be drawn. Koch I
determines the limits OF tempcrture be-
tween which the tubercle-JaciIlus can de-
veIop and multiply. The minimum tenn
pcrature he finds to be $50 Fahrenheit, and
the maximum l04o. lie concludes that,
unlike the bacillus dntkrGcis Of splenic
fever, which can flourish freely outside
the animal body, In the temperate zone
animal warmth II necessary for the
propagation OF the newly-discoyered or
gsDisn. In vast number OF cases
Koch has examined the matter expecto-
rated from the lungs OF persons affected
ssnh, .phthisis, and found In II swarins OF
~ while in matter expectorated from
lungs OF persons not thus afflicted he