124 
MINUTE ORGANISMS. 
ularly supposed that animalcule, or wliat are commonly em¬ 
braced under the vague name of infusorise, inhabit the water 
alone, but the atmospheric dust transported by every wind 
and deposited by every calm is full of microscopic life or of its 
relics. The soil on which the city of Berlin stands, contains 
at the depth of ten or fifteen feet below the surface, living 
elaborates of silex; * and a microscopic examination of a 
handful of earth connected with the material evidences of 
guilt has enabled the naturalist to point out the very spot 
where a crime was committed. It has been computed that 
one sixth part of the solid matter let fall by great rivers at 
their outlets consists of still recognizable infusory shells and 
shields, and, as the friction of rolling water must reduce much 
of these fragile structures to a state of comminution which 
even the microscope cannot resolve into distinct particles and 
identify as relics of animal or of vegetable life, we must con¬ 
clude that a considerably larger proportion of river deposits is 
really the product of animalcules.f 
It is evident that the chemical, and in many cases the 
mechanical character of a great number of the objects impor¬ 
tant in the material economy of human life, must be affected 
by the presence of so large an organic element in their sub¬ 
stance, and it is equally obvious that all agricultural and all 
industrial operations tend to disturb the natural arrangements 
of this element, to increase or to diminish the special adaptation 
of every medium in which it lives to the particular order of 
* Witt wee, Pliysilcalische Geographic, p. 142. 
t To vary the phrase, I make occasional use of animalcule, which, as a 
popular designation, embraces all microscopic organisms. The name is 
founded on the now exploded supposition that all of them are animated, 
which v r as the general belief of naturalists when attention was first drawn 
to them. It was soon discovered that many of them were unquestionably 
vegetable, and there are numerous genera the true classification of w T hich 
is matter of dispute among the ablest observers. There are cases in which 
objects formerly taken for living animalcules turn out to be products of the 
decomposition of matter once animated, and it is admitted that neither 
spontaneous motion nor even apparent irritability are sure signs of animal 
life. 
