Evening star., 1922-02-25
PLANT LIFE AND
DEATH. MEASURED
Harvard Biologists Made
Stride in Light on Injury
and Recovery.
BY the Associn ted Press.

| CAMBRIDGE. Mass, February 20
Harvard biologists have succeeded in
measuring for the first time with
scientific precision the processes of
lie and death as they appear In
plants, the university announced to-
| DAY. 1t was said experiments already
made may throw light on certain
phenomena of injury and recovery In
human beings which up to this time
! have not been entirely clear.
These experiments made by Prof.
W. J. V. Osterhout of the de-
partment of botany show that 1t is
possible to study the behavior of liv-
Ing organisms with the same mathe-
matical exactness with which chem
lists and physicists study that of in
animate matter. thus taking two OF
NE and death. and giving them guam
tltat!ve significance which can be
! expressed in figures.
Electrical Resistance Index
Tho experiments have been made
upon Lar 1.arfa, one of the common
brown ~ ps of the Atlantic coast 1t
has been found that the resistance of
this plant 10 a current of electricity
is an excellent index to its normal
condition of vitality.
When the plant is alive it resists
the current. When dead, II does not
If the plant is injured. the electrical
! resistance at once decreases. :.
BY measuring the exact amount of
electrical resistance under various
circumstances. the Harvard biologists
are able to plot curves which show
precisely the effects Of various kinds
Of injuries, the extent of recovery and
| the manner in which the plant dies.
Resistance Falls Steadily.
If. for example. the plant is taken
from sea water and placed in a solu-
tion of pure sodium chloride. it is
quickly injured. and IL the exposure
be sufficiently prolonged it is killed.
During the whole time of exposure
to the solution of sodium chloride the
electrical resistance falls steadily in
definite curve until the death point
is reached, after which there is no
further change.
A significant discovery is that il the
| injury is only slight, the plant fully
| RECEIVERS. Its electrical resistance re-
| turning to normal afterward. where
| as. if the injury is sufficiently severe
| the plant only partially recovers its
vitality, and for the rest of its life
has diminished electrical resistance
| An exposure of two hours in the So
| luton of sodium chloride will kill
| the plant. From an exposure of five
tucIo ID COiIlplel6 recovery.
From one of an hour there is only
partial recovery. Prof. Osterhout has
found 1t possible to predict exactly
| the extent OF recovery from any given
| injury.
Obey Dynamics Laws.
The investigation of funda mental
| life processes, it was said at Harvard,
show that they appear to ooey the
| laws OF chemical dynamics, and Illus
trates a method of attack which may
| throw some light upon the underly-
ing mechanism of these processes and
assist materially in the analysis AID
control of life phenomena. Ultimate
ly it may be possible to predict ccr-
tain aspects of the behavior of living
matter. immensely complicated as IL
is. in some such exact way as 1t is
now possible to predict the course of
the tides, which are also immensely
| complicated because they depend upon
many variables, such as the movement
of the moon. the temperature and the
. confiSuration of the shores.