1 
BACTERIA IN THE HUMAN MOUTH 243 
I have also put a little wine-vinegar to this stuff mixed 
with spittle, or with water: whereupon the animalcules 
fell dead forthwith. And from this I drew the conclusion 
that the vinegar, when I filled my mouth with it, didn’t 
penetrate through all the matter that is firmly lodged 
between the front teeth, or the grinders, and killed only 
those animalcules that were in the outermost parts of 
the white matter. 
In several of the observations aforesaid, I saw on 2 or 
3 occasions some very bright transparent particles, 
whereof many were perfectly round, others having an 
irregular round figure. ‘These were of divers bignesses, 
and the biggest of them I judged to be about 25 times 
bigger than a globule of one’s blood’: and if they hadn’t 
sunk to the bottom, by reason of their weight, I should 
have taken them for fat-particles.’ 
I have had several gentlewomen in my house, who 
were keen on seeing the little eels in vinegar: but some 
of ’em were so disgusted at the spectacle, that they vowed 
they’d ne’er use vinegar again. But what if one should 
tell such people in future that there are more animals 
living in the scum on the teeth in a man’s mouth, than 
there are men in a whole kingdom ? especially in those 
who don’t ever clean their teeth, whereby such a stench 
comes from the mouth of many of ’em, that you can 
scarce bear to talk to them; which is called by many 
people “ having a stinking breath”, though in sooth ’tis 
most always a stinking mouth. For my part I judge, from 
myself (howbeit I clean my mouth like I’ve already said), 
that all the people living in our United Netherlands are 
not as many as the living animals that I carry in my 
own mouth this very day: for I noticed one of my back 
teeth, up against the gum, was coated with the said matter 
z.e., they had about thrice the diameter of a human red blood-corpuscle. 
These were probably squamous cells—the smaller being “salivary 
corpuscles ” (dead leucocytes). 
2 
vet-deeltgens ; 2.e., oil droplets. 
