Evening star., 1938-10-04
OF STARS,
MEN AND ATOMS
Notebook of Science Pro&ress
in Field, Laboratory
and Study.
By THOMAS r. HENRY.

to time about suspended animation by
freezing with the wierd prospect Of put
ting man or dog In an ice box, keep
Ing him there few centuries and then
thawing him out as young and vigorous
as ever.
The idea involves, at the outset, q
physical impossibility - instantaneous
freezing of the water in the cells into q
solid state without the formation OF ice
crystals. About as near an approach as
can be made at present, and with very
practical side since it makes possible
absolutely fresh fish for inland commu-
mites, is described in report to the
by Drs. P. j. Schmidt and G. P. Platonov
OF the governments Refrigeration In
stitute.
Fish, according to this report, actually
have been placed in state Of suspended
animation for five days or more, during
which they can be shipped for long dis
tances, and then brought back to life.
AS the two Russian scientists describe
their experiments:
Our investigations have shown that
fishes, when frozen in water, always
perish, but when frozen dry can later
revive on being thawed, provided that
only the outermost layer OF their body
is frozen and that the formation of ice
crystals In their interior parts has not
yet begun. When the inner parts Of
the body begin to freeze, and especially
when complete freezing occurs, the fish
can never be revived. 1t Is, moreover,
impossible to check the process of freez-
ing OF fishes at its first stages, when the
surface layers alone are frozen; for at
low temperatures of the surrounding air
from-10 to-l5'C) the process con-
tinues to completion and the fish per-
1Shes. At the same time our investiga-
tions showed that neither the freezing
fish in water nor its dry freezing is ap-
plicable for practical purposes OF trans
port and cold storage.
This induced us to start experiments
OF chilling fishes to 0'C. Our first OBJ
servations Of small crucian carps chilled
in ice water showed that near o. there
sets In state Of torpor and the gill
covers cease all respiratory movements,
the fishes looking like dead. The fishes
can remain in the water for hours in
such state and then revive on being
transferred to warmer water. A pro-
longed stay in cold water, however fire.
quently kills the fishes. In subsequent
experiments we therefore took the fish
out Of the water as soon as the torpor
had set in and then placed it on ice in q
moist atmosphere. We employed ordi-
nary thermoS bottles for this purpose.
We filled them with crushed ice, placed
fishes therein, closed them tightly, and
kept them at room temperature or placed
In, prXvnS bot NIT
giving melting temperature ranging
from-30.9 to-ll'.l. At room tempera-
ture the ice in the thermos bottle held
for two days and in the cryostat for up
to 10 days. These experiments showed
the possibility of preserving small cru
clan carps and bleaks in lifeless state
for a period OF up to 10 days with their
subsequent revival on being transferred
into warm water. Table / summarizes
the results Of these experiments.
Most propably 10 days is not the limit
for the preservation of vitality in fishes
under the conditions described above,
but owing to purely technical causes we
could not preserve the ice for a longer
period without thawing. And when the
fish gets into the water produced by the
thawing ice, Its vital processes are re-
sumed and it perishes from lack of
oxygen.
For the purpose Of determining in
how far the life processes of fishes can
be suspended by chilling as described, we
made experiments Of keeping the fish in
a nitrogen atmosphere. In these tests
the fish was placed in a thermos bottle
filled to two-thirds with ice prepared
from distilled water; a current of pure
nitrogen was then passed for 80 minutes
through the thermoS bottle which was
then tightly corked and sealed with
paraffln: 1912 hours later nitrogen was
again passed through the thermos bottle.
1T is highly probable that also in this
case 48 hours do not constitute the limit
for conservation in nitrogen under the
conditions described, but we did not sue
ceed in preserving the ice for a longer
time without thawing. The experiment
shows, in any case. that life activity in
fishes and their gas exchange are ex-
tremely depressed. A more detailed
study Of the physiological state OF the
fishes will be made by us subsequently.
The experimental conservation on ice
OF larger fishes was fraught with great
difficulties owing to the impossibility
under our laboratory conditions of main
tanning constant temperatures close to
0'C for prolonged periods. We sue
ceeded in setting up such conditions for
fishes 14-28 en-. in length for periods Of
not over "a hours, and only in test No.
1925 a crucian carp placed into an ice
block was maintained at 00C for 10 hours
40 minutes.
These experiments show that large
fishes las carps and crucian carps) can
also preserve their vitality for period
OF "a hours and more.
"On the basis of above experimental
results we made two experiments of
transporting chilled fish on ice. In Sep
tember, 1896, G. P. Platonov carried out
at the Oranjereini fisheries, near As
trakhan, series Of preliminary expert
ments with surgeons, which showed that
large surgeons, from rs to 80 en-. in
length, chilled to 0'C in ice water for
two hours fell into torpor with cessa-
ton Of respiratory movements. When
packed in such state on ice in tightly
closed insulated box, they can be kept
for "a hours and~then revive on being
transferred into water at -t15'C. On
September %, 1896, five surgeons taken
out of a floating fish tank were placed
in two tubs filled with water of + 49,
SC; by adding ice the temperature Of the
water was lowered to 0'C in As minutes
and the fishes after certain period OF
restlessness quieted down and fell into