ANIMALCULE. 
us. A mite was anciently thought the limit 
of littleness ; but we are not now surprised 
to be told of animals twenty-seven millions 
of times smaller than a mite. Minute ani- 
mals are found proportio’nably much strong- 
er, more active and vivacious than large ones. 
The spring of a flea in its leap, how vastly 
does it outstrip anything greater animals are 
capable of! A mite, how vastly faster does it 
ran than a race-horse ! M. de l’Isle has 
given the computation of the velocity of a 
little creature scarcely visible by its small- 
ness ; which he found to run three inches 
in half a second : supposing now its feet to 
be the fifteenth part of a line, it must make 
five hundred steps in the space of three in- 
ches ; that is, it must shift its legs five hun- 
dred times in a second, or in the ordinary 
pulsation of an artery. The excessive mi- 
nuteness of microscopical animalcules con- 
ceals them from the human eye. One of 
the wonders of modern philosophy is, to 
have invented means for bringing creatures 
to us so imperceptible under our cogni- 
zance and inspection : an object a thousand 
times too little to be able to affect our sense 
should seem to have been very safe. Yet 
we have extended our views over animals, 
to whom these would be mountains. In 
reality, most of our microscopical animal- 
cules are of so small a magnitude, that 
through a lens, whose focal distance is the 
tenth parth of an inch, they only appear as 
so many points ; that is, their parts cannot 
be distinguished, so that they appear from 
the vertex of that lens under an angle not 
exceeding a minute. If we investigate the 
magnitude of such an object, it will be found 
nearly equal to of an inch long. Sup- 
posing, therefore, these animalcules of a cu- 
bic figure, that is of the same length, breadth, 
and thickness, their magnitude would be ex- 
pressed by the cube of the fraction Too oocU 
that is, by the number juoo^o ju,uod,ouo, ouo ? that 
is, so many parts of a cubic inch, is each 
animalcule equal to. Leeuwenhoeck calcu- 
lates, that a thousand millions of animalcula, 
which are discovered in common water, are 
not altogether so large as a grain of sand. 
This author, upon examining the male sperm 
of various animals, discovered in many in- 
finite numbers of animalcula not larger than 
those above mentioned. In the milt of a 
single cod fish there are more animals than 
there are upon the whole earth ; for a grain 
of sand is bigger than four millions of them. 
The white matter that sticks to the teeth 
also abounds with animalcules of various fi- 
gures, to which vinegar is fatal ; and it is 
known, that vinegar contains animalcules in 
the shape of eels. In short, according to 
this author, there is scarcely any thing which 
corrupts without producing animalcules. 
Animalcules are said to be the cause of va- 
rious disorders. The itch is known to be 
a disorder arising from the irritation of 
a species of animalcula found in the pus- 
tules of that ailment: when the commu- 
nication of it by contact from one to an- 
other is easily conceived, as also the reason 
of the cure being effected by cutaneous ap- 
plications. In the Philosophical Transac- 
tions, vol. lix., is a curious account of the 
animalcules produced from an infusion of 
potatoes, and another of hemp-seed, by the 
late Mr. Ellis.” « On the 25th of May, 1768, 
Fahrenheit’s thermometer 70°, I boiled a po- 
tatoe in the New River water, till it was re- 
duced to a mealy consistence. I put part 
of it, with an equal proportion of the boil - 
ing liquor, into a cylindrical glass vessel, 
that held something less than half a wine- 
pint, and covered it close immediately with 
a glass cover. At the same time I sliced 
an unboiled potatoe, and, as near as I could 
judge, put the same quantity into a glass 
vessel of the same kind, with the same pro- 
portion of New River water not boiled; 
and covered with a glass cover, and placed 
both vessels close to each other.” “ On the 
26th of May, 24 hours afterwards, I exa- 
mined a small drop of each by the first mag- 
nifier of Wilson’s microscope, whose focal 
distance is reckoned at part of an inch ; 
and, to my amazement, they were both full 
of animalcula, of a linear shape, very distin- 
guishable, moving to and fro with great ce- 
lerity, so that there appeared to be more 
particles of animal than vegetable life in 
each drop.” “ This experiment I have re- 
peatedly tried, and always found it to suc- 
ceed in proportion to the heat of the cir- 
cumambient air; so that even in winter, if 
the liquors are kept properly warm, at least 
in two or three days the experiment will 
succeed.” “I procured hemp-seed fr om dif- 
ferent seeds-men in different parts of the 
town. Some of it I put into the New Ri- 
ver water, some into distilled water, and 
some into very hard pump-water. The re- 
sult was, that in proportion to the heat of 
the weather, or warmth in' which they were 
kept, there was an appearance of millions of 
minute animalcula in all the infusions ; and, 
some time after, oval ones made their ap- 
pearance. These were much larger than 
the first, which still continued : these wrig- 
