Evening star., 1942-02-21
Of Stors, Men
And Atoms
Notebook Of Science Progress
In Laboratory, Field
And Study
BIZ Thomas r. Henry.

By Thomas r. Henry.
About so days are required to replace
fully the pint of blood which thousands
OF Americans now are giving to the Red
Cross for the Army and Navy.
For the average healthy individual
| there are no bad effects.
These conclusions have just been re-
ported to the American Medical Associa-
tion by Drs. Willis M. Fowler and Ade-
| laide p. Berer of Iowa State University.
They are based on tests with 200 blood
donors, mostly robust young medical STU
dents. The doctors determined the rate
Of regeneration of hemoglobin, the IRON
containing red pigment in blood. which is
the carrier Of oxygen to the tissues.
1t was found that the average healthy
man regained the lost hemoglobin within
so days without any treatment. Those
whose blood was especially rich in the
pigment recovered at about the same
rate as the others. In other words, the
experimenters say. there is no way of
determining beforehand how soon a per-
son will recover.
Subsequent blood donations, they say,
may be given with safety as soon as the
hemoglobin has returned to its original
level, regardless of the elapsed time. In
the majority Of donors an interval of
two months will suffice, but about Is per
cent Of our series required a longer
period. We did not feel that the regen-
Grafton of hemoglobin became slower
after multiple donations than 1t had been
after the first.
THE administration of small amounts
Of iron had a surprising effect. The rate
Of regeneration was increased nearly so
per cent and there was drastic shorten
ing of the recovery period. so that subse-
quent blood donations were possible after
much shorter interval. With this medi-
cation the blood hemoglobin content in
93.5 per cent Of the subjects returned to
normal by the end of eight weeks
THE effect of the iron, however, was
transient. The donor was benefited only
for one or two recovery periods, so that
continued administration did not main
tain the rate Of regeneration above the
original. There was no evidence of the
exhaustion of the bone marrow (where
red blood cells are formed while the sub
jects were under observation.
The rate of regeneration was slightly
less rapid in women than in men,
and the time necessary for recovery was
somewhat longer. Female donors should
be allowed longer intervals between
donations"
DR.. Charles Ridley, director of the
Singapore Botanical Gardens, in 1905
made one Of the greatest discoveries in
industrial history-the so-called wound
reaction" Of the hitherto despised hevea
tree.
When the Brazilian rubber tree was
tapped, very small amount of latex
would ooze from the wood coagulate and
close the wound. 1t was not considered
q worthwhile source Of the material for
which the world demand was increas-
ing so rapidly.
DR.. Ridley found that when the crust of
latex was shaved of, after a day or two,
the flow would increase. When the
process was repeated several times there
would result constant flow far greater
than that from any other rubber plants.
Naturally, extensive paintings were
made in Malaga. But the charge that
the British and Dutch deliberately
| plotted together to steal the New World
rubber crop is hardly fair 1t was pure
happenstance that the wound reaction
~, Il,
| leaf blight was unknown in that part of
the world. Actually, the first plan was
| to develop the crop, with improved varie-
ties from Wickham's Seeds in British and
Dutch Guiana. Thousands of acres were
planted.
The leaf blight disease wiped out the
| plantations in few years. The inves-
tors were ruined. Rubber producers
turned rather reluctantly to the Far
East again.
Brazil has been criticized for allowing
what now is perhaps the worlds most
valuable crop to slip from her hands.
Actually. she had no choice. Not even
the British or the Dutch could raise
rubber in South America, in view of the
primitive state of the science of plant
breeding at the time.
1t must always be remembered, Depart
| ment of Agriculture rubber specialists
say, that If it had not been for the
Malayan plantations, with their freedom
from leaf blight, development of the
American automobile industry would
have been impossible.
| Breeders improved the yield. Hevea
was overplanted The price of rubber
fell below the possibility Of profitable
production. British and Dutch were
forced to defend themselves against out
side competition.
Before 1884 they had shared their
scientific improvements freely with the
world An American tire company OBJ
tanned all of their choicest varieties in
1888 and started plantations in the
Philippines. The next year Great Brit
ain, Holland, France and Siam concluded
an agreement to allow no more seeds or
seedlings to be exported.
Fortunately, large stock of the best
varieties up 10 1884 was propagated in
the Philippines. 1t is from this stock
that millions of "clones"-bud-grafte
seedlings-have been brought to South
America in the past two years. The last
large shipment arrived safely at San
Francisco few days after the Pearl Har-
Dor disaster. The plants are the result Of
80 years Of extensive research. Some
better ones have been reported from
| AEoy ci hou