Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1882-05-22
TYEDALL ON KocHs WORK.
A Subject Of the Gravest Public Import.

T1hDALL On kOCHS WORK,
A Subject of the Gravest Public Import.
auce
PROF. John Tyndall in the London Timesl
On the oath of March, 1882, an address
of very serious public import was delivered
by DR.. Koch before the Physiological So.
ciety of Berlin. 1t touches question in
which we are all at present Interested
that of experimental physiology-and l
may, therefore, be permitted to give some
account of it in the Times. The address, a
copy of which has been courteously sent to
me by its author, is entitled 1.-The Etiology
of Tubercular Disease" 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 infection 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 trans
ferred from modest country practice, in
the neighborhood of Breslau, to the post
of Government Adviser in the Imperial
Health Department of Berlin. From this
department has lately issued most i'm.
portant series of
INVESTIGATIONS
On the etiology of infective disorders.
Koch's last inquiry deals with disease
which, in point OF mortality, stands at the
head OF them all. If, he says, the serious.
ness OF malady be measured by the mum.
Der OF its victims, then the most dreaded
pests which have hitherto ravaged the
IL Il
stand far behind the one now under con.
sideration. 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 pre-.
else character of the contagium which pre-.
vious experiments on inoculation and in
halation had proved to be capable of in.
definite transfer and reproduction. He
subjected the diseased organs of great
number OF men and animals to microscopic
examination, and found, in all cases, the
tubercles infested with minute,
ROD. SHAPED PARASITE,
Which, by means of special dye, he
differentiated from the surrounding tissue
1t was he says, in the highest degree i'm
pressive to observe in the center of the
tubercle cell the minute organism which
had created it. Transferring directly, 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 par.
asite itself, but some virus in which it was
imbedded in the diseased organ-that was
the real contagium-he cultivated his
bacilli artificially for long periods of time
and through many successive generations.
With speck of matter, for example, from
tuberculous human lung, he infected
substance prepared, after much trial, by
himself, with the view of affording nutri-
ment to the parasite. Here he permitted
it to grow and multiply. From this new
generation he took a minute sample and in
fected Herewith fresh nutritive matter,
thus producing another brood. Generation
after generation of bacilli were developed
in this way without the intervention of
disease. At the end of the process, which
sometimes embraced successive civilizations
extending
OVER HALF A YEAR,
The purified bacilli were introduced into
the circulation of healthy animals of va
rious 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 |
a further, though still brief and sketchy, |
account of Koch's experiments. OF six
Guinea pigs, all in good health, four were
inoculated with bacilli derived originally I
from human lung, which, in fiftY.four
days, had produced five successive gener I
ations Two of the six animals were not T
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 remain.
ing five were killed and examined. In the
Guinea pig that died, and in the three re-
infected ones, strongly. pronounced |
disease had set in. Spleen, /
liver and lungs were found filled with
tubercles while in the two uninfected /
animals no trace of the disease was OBJ
served.
IN SECOND EXPERIMENT,
Six out of eight guinea pigs were inocu-
lated with bacilli, derived originally from
the tuberculous lung of q monkey, bred
and rebred for 90 days, until eight genera.
tions had been produced. Every one of
these animals was attacked, while the two
uninfected guinea pigs remained perfectly
healthy. Similar experiments were made
with cats, rabbits, rats, mice, and other
animals, ard, without exception, it was
found that the injection of the parasite
into the animal system was followed by
decided and, in most cases, virulent tuber-
cular diseases. In the cases thus far men,
toned incubation had been effected in the
abdomen. The place of incubation was
changed to the aqueous humor
of the eye. Three rabbits received each a
speck of bacillus culture, derived originally
from human lung affected with pneumo.
MIA. Eighty-nine days had been devoted
to the culture of the organism.
THE INFECTED RABBITS
Rapidly lost flesh. and after % days were
killed and examined. The lungs of every
one OF them were found charged with
tubercles. OF three other rabbits, one re-
ceived an injection of pure blood-serum in
the aqueous humor Of the eye, while the
other two were infected, in similar way, |
with the same serum, containing bacilil, |
derived originally from diseased lung
and subjected to 81 days cultivation.
After 2S days the rabbits were killed.
The one which had received an injection
of pure serum was found perfectly healthy,
while the lungs of the two others were
found overspread with tubercles.
OTHER EXPERIMENTS
Are recorded in this admirable essay, from |
which the weightiest practical conclusions
may be drawn. Koch determines the
limits of temperature between which the |
tubercle- bacillus can develop and multiply. |
The minimum temperature he finds to be
So. He concludes that, unlike the bacil-
lus anthracis of splenic fever, which can
flourish freely outside the animal body, in
the temperate zone animal warmth is nec-
essary for the propagation OF the newly dis
novared nroanism In a vast number |