Echolocation and scurvy: facts before explanations.
OF THE ROYAL SOCIETY
matter of vitamin D deficiency secondary to fat malabsorp-
steatorrhoea is much more severe, and in any case the main
source of vitamin D is the irradiated skin. Perhaps vitamin
K has a role, or malabsorption of calcium per se.
John A Davis
1 Cambridge Road, Great Shelford, Cambridge CB2 5JE, UK
itis,all, rare in cystic fibrosis in which
Euthanasia in the Netherlands
Dr Zylicz and Professor Finlay (July 1999 JRSM, pp. 370-
373) state that 'An analysis of 200 consecutive cases yielded
insight into these [euthanasia] requests.' From this they cite
two groups (3 and 5), 'both less than 1%...', which can
only mean that each group contained just one case. The
authors characterize the third group as 'tend to be young, in
managerial or other senior positions, whose normal lifestyle
involves being in control and taking complex decisions.
frequently neglecting the emotional needs of partner and
children, with whom a balanced discussion of choices may
be difficult to achieve.'
This seems to be a wildly extravagant, even gratuitously
damning, description of the personal characteristics of this
'group' that appears to have been made from the analysis of
just one case.
Wynd House, Hutton Rudby, North Yorkshire TS15 OES, UK
In the original, retrospective, study ZZ found two patients
However, when this study was finished such patients were
found to be over-represented in the Dutch cohort compared
with the patients later admitted to the hospice. This was
why we used the descriptor of 'less than 1%' as this article
was not the study report. We accept it would have been
clearer to use the term '1%'.
Control-orientated patients appear to seek help from the
hospice in Holland relatively infrequently. On discussing
the data with Dutch general practitioners, it is evident that
this type of patient forms a significant and recognizable
cohort in their clinical practice. Together with these general
practitioners ZZ developed a description of the 'control-
orientated' group; this description was evolved from the
consensus view of the general practitioners.
Thesepatients, who are usually young, encounter
understandably enormous emotional difficulties in facing
their own death. When making a decision about euthanasia,
they find it painful to contemplate conflicting needs from
their family, particularly any children, who also suffer
anxiety. We do not
response to their plight; we simply wish to point to the
professionals by this type of situation. The death of the
patient is not the solution.
Hospice Rozenheuvel, Rosendaalselaan 20, 6891 DD Rosendaal, Netherlands
Holme Tower Marie Curie Centre, Penarth, Vale of Glamorgan CF64 3YR, Wales,
Echolocation and scurvy:
facts before explanations
In his review of a book on Louis Jurine (August 1999JRSM,
pp. 433-434), Mr Marston mentions Jurine's work on bats.
community to accepting facts that cannot yet be explained1.
In 1793 Spallanzani found that bats could fly accurately
when blinded. Jurine proved that they still needed their
ears. Spallanzani then proved that they needed neither
vision nor touch, but did need both ears and mouth
unblocked. Their work was ridiculed, lost sight of, and
repeated in 1900 and 1908 by scientists unaware of their
predecessors, again without being followed up. It was only
after echolocation techniques had been used extensively by
shipping that this mechanism was finally suggested for bats
by Hartridge in 1920, proved in the 1940s by Griffin and
Galambos and by Dijkgraaf, and accepted generally.
A more disastrous example is the prevention and/or cure of
scurvy by citrus fruits2. Whitehead lists thirty-seven reported
observations of this between 1497 and 1793. The point was
made clearly in areport on Cabral's voyage to India published in
1507. But since deficiency diseases were unknown as such, the
repeatedly reported facts were ignored, and useless remedies
applied, for three centuries. In this case the incentive was so
compelling that by 1793 lemon juice was regularly issued to
British East India fleets, over a century before the concept of
vitamins was introduced by the Polish scientist Funk in 19123.
But the three-century delay had cost an estimated two million
deaths at sea.
The lesson is clear. Good empirical evidence, whether
experimental or clinical, should be accepted and acted
upon, whether or not it can be explained in terms of
current scientific knowledge.
W M S Russell
Department of Sociology, University of Reading, PO Box 218, Reading RG6 2AA,
Griffin DR. Listening in the Dark: the Acoustic Orientation of Bats and Men.
New Haven: Yale University Press, 1958
Whitehead PJP. The citrus cure for scurvy.
Pledge HT. Science since 1500: a Short History of Mathematics, Physics,
Chemistry, Biology. London: HMSO, 1940:245
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