Savory - Arachnida 1977

34
Medical Arachnology
The medical aspects of Arachnology may begin with a reference to
Nicander, a physician of the second century B.c., a native ofClaros, near
Colophon (the home of Arachne herself). He was the author of Theriaca,
a long poem which included the treatment of a bite from a spider.
A few of his hexameters seem to refer to the effects of a Latrodectus
bite. His doctoring was recorded by Pliny (A.D. 23-79), advising the
application of a cock's brain in vinegar, or a sheep's droppings, also in
vinegar.
Spiders themselves were valued by the medical men of the day. The
"wolf spider" applied to the forehead in a compress of resin and wax was
recommended as a cure for tertian fever. Further, "a spider descending
on its own thread, taken in the hollow of the hand, crushed and applied
'appropriately' acts as an emmenagogue, but if the spider is taken as it
is climbing upwards it has the opposite effect."
Both Pliny and his contemporary Dioscorides wrote of the value of
"cobweb" for stopping the flow of blood from a cut or small scratch.
References to this have continued to appear ever since, and the effectiveness
of spider-silk in such small emergencies is universally recognized.
Its persistence has been remarkable.
In "A Midsummer Night's Dream" Bottom says, "Good ~faster
Cobweb, if I cut my finger, I shall make bold with you" (3.i.90), and
the practice was mentioned by both the early British naturalists Edward
Topsel and Thomas Moffett (1553-1604). It is to be found in the Diary
of Charles Ashmole for 11th April, 1681 and was advised by John
\Vesley in "Primitive Physic", 1762.
The viability of this trust in cobwebs as a styptic provokes the need to
explain its action. On one point all are agreed; that no qualified medical
practitioner today would think of prescribing it, but would not deny its
value in an emergency. Even now, stablemen are sometimes advised
not to clear away the cobwebs in the stable-"You never know when
you may need them"-a fact that underlines the surprising absence of
34. MEDICAL ARACHNOLOGY 289
recorded bacterial infection from the web. Spiders' webs can hardly
be sterile.
A simple and possible explanation is that the action of the threads
is no more than a mechanical one, having the effect of favouring the
deposition of fibrin. In this case, comparison with the help of a piece of
cotton wool is obvious. The "mechanical effect" is most probably an
example of the result of distributing unclotted blood over a \vide area,
which is found to provide a base on \vhich platelets are quickly deposited.
This is applied in the modern use of several synthetic materials
in sponge form, placed in contact with bleeding surfaces.
Enquiry has, however, carried the subject a stage further. A number
of substances of widely differing composition have been shown to function
as activators of the Hageman factor, which in turn initiates the
clotting mechanism. Among those quoted are kaolin, barium carbonate,
asbestos, carboxymethyl cellulose and calcium pyrophosphate, as well
as spider-silk. It is not impossible that this is connected with the fact that
platelets carry a negative charge, and are deposited electrostatically
whenever positively charged surfaces come into contact with them.
The clotting of blood is a complex process, and it seems that the last
word on the action of cobwebs or silk has not yet been heard.
Returning now to the eighteenth century, the practice ofhomoeopathy
deserves attention. This svstem of medicine was introduced bv Samuel
Hahneman in 1796, and ~ne of its fundamental principles was the use of
drugs in very small quantities. Spiders receive special attention. The
venom from Tarentula hispana is said to influence the nerves supplying
the human uterus and ovaries, and to be a remedy for hysterical conditions
and similar nervous complaints. Tarentula cubensis is similarly
described as a cure for abscesses and swellings of any kind. Venom from
M;'gale lasiodora is the basis of a remedy for chorea, but Araneus diadematus
is more efficacious when the symptoms are aggravated by wet
weather.
Few spiders, hmvever, have so fully occupied the attention of the
medical profession as has the well known tarantula.
The true tarantula, Lycosa tarentula, is widely distributed in southern
Europe. Its headquarters, metaphorically and historically, cover an
area round the town ofTaranto, on the shore of Apulia in south Italy;
and it was here, according to one Pietro :\Iatthiole of Sienna, that the
first case of tarantism was recorded in 1370.
Tarantism was the name given to the remarkable effects that were
alleged to follow the bite of this spider, and which could be cured only
by music and dancing. By the end of the fifteenth century tarantism had
spread over the whole of Apulia; thence it continued its course, covering
all Italy and reaching its height about 1650. By the end of the