GETTING SMELLY FOR SCIENCE
Although self-experimentation was not unique for this era, Leeuwenhoek is especially remembered for his peculiar
and sometimes smelly home-based experiments.
GrUbBy lIcE LeGs
To observe and describe a louse
feeding, Leeuwenhoek let a louse sit
on his hand and draw blood from
him so he could observe how it fed.
Super, super gross. Ed.
In 1683, Leeuwenhoek made
observations about plaque on
teeth. He didn’t clean his teeth for
three days and then collected his
own plaque for observations. He
also continued his observations by
collecting plaque from two women
and two men who had never
cleaned their teeth before. (Super
gross. Ed.) He looked at all of the
specimens under his microscope
and wrote about each one.
He described the plaque of one of
the men by saying:
‘an unbelievably great company of
living animalcules, a-swimming more
nimbly than any I had ever seen up to
this time’
If you think that is disturbing then
you may not want to read on...
Leeuwenhoek conducted another
lice experiment in which he put adult
lice on his leg and covered them with
his stocking then left that stocking
on and didn’t have a wash for six
days. After six days he removed his
sock and observed over 80 louse
eggs stuck to his leg hair. But it
doesn’t stop here, brace yourself for
feeling itchy...
Leeuwenhoek then put the sock back
on and left it on for another four days
with no washing (I make that a
total of ten days without a
wash...) . The result was that he had
at least 25 young lice living on his
leg. At the end of the experiment
he felt so disgusted by it all that he
threw his lice-filled sock out of the
window and then cleaned his leg by
rubbing it with ice two times. (Bath?
soap? Maybe he should be called
Peew-enhoek? Ed.) Based on his
findings he calculated that in just
eight weeks, two lice could become
ten thousand young lice on a ‘Person,
who does not have a change of linen or
garments.’
The sketches in his notebook of
‘animalcules’ in the mouth are
described today as microorganisms.
The ones he saw specifically include
oral bacteria. This finding was the
gateway to the amazingly complex
world that exists within the human
mouth.
SwEaT CoLlEcToR
Leeuwenhoek also designed an
experiment to find out how much
water is regularly lost through the
skin in a day. To do this he
weighed a dry beaker then put
his own hand inside it and used a
handkerchief to seal the top of
the glass. He watched moisture
condense on the inside of the
glass. Finally he was able to
weigh the sweat he had collected
from himself and, based on the
surface area of his hand, he
calculated how much vapour was
excreted. From this he estimated
that the whole body must
produce 28 fluid ounces (828 ml)
every 24 hours.
A few of Leeuwenhoek’s other
peculiar experiments:
● When he was ill he examined
his own tongue and saw it had a
furry texture. He scraped the
white substance off his tongue
and looked at it under the
microscope for observation.
● He examined pepper water,
river water, snow water, rain
water, dirty water from a well
near his house and sea water
collected for him by a stranger.
Often leaving it out a number of
days and examining it regularly.
● He also observed cheese fungi,
animal sperm, animal bile liquid,
urine and exploding gun
powder. (Super super super
gross. Ed.)
Cathro
TeEtH ScRaPiNg