214 - 
lecture XII. 
Microscope, have discovered whole tribes of ani- 
mals, compared to which even Mites may be con- 
sidered as a kind of Elephants. These minute 
beings are chiefly to be observed in fluids of vari- 
ous kinds ; and principally in such as have had any 
animal or vegetable substances infused in them; 
and for this reason they are often called in modern 
Zoology by the title of Animalcula Infusoria or 
Infusorial Animalcules. A most extraordinary 
idea was entertained by the celebrated Count de 
Buffon, relative to these Animalcules ; viz. that 
they were not real animals, but a kind of organic 
particles or Moleculae, which were capable, under 
certain circumstances, of being formed into ani- 
mated beings. The experiments of Spallanzani 
and others have however completely overthrown 
this chimerical and absurd theory of the Count de 
Buffon ; and indeed one would hardly think it pos- 
sible for any person of unprejudiced mind, nay 
one may even add, of common sense, to view the 
several animalcules in fluids, and at the same time 
to doubt of their being real animals. Their rapid 
and various motions j their pursuit of the smaller 
kinds on which many of the larger prey; their 
avoiding each other as they swim; the curious 
