_MADAM,_
Having made some mention in my former Letter of the Receiving of Food,
and discharging of Excrements, as also of Respiration, which consists
in the sucking in of air, and sending out of breath in an animal body;
you desire to know, _Whether Respiration be common to all animal
Creatures?_ Truly, I have not the experience, as to tell you really,
whether all animals respire, or not; for my life being, for the most
part, solitary and contemplative, but not active, I please my self
more with the motions of my thoughts, then of my senses; and therefore
I shall give you an answer according to the conceivement of my reason
onely, which is, That I believe, all animals require Respiration; not
onely those, which live in the air, but those also, which live in
waters, and within the earth; but they do not respire all after one
and the same manner; for the matter which they imbreath, is not every
where the same, nor have they all the same organs, or parts, nor the
same motions. As for example: Some Creatures require a more thin and
rarer substance for their imbreathing or inspiring, then others, and
some a more thick and grosser substance then others, according to
their several Natures; for as there are several kinds of Creatures,
according to their several habitations or places they live in, so they
have each a distinct and several sort of matter or substance for their
inspiration. As for example: Some live in the Air, some upon the face
of the Earth, some in the bowels Earth, and some in Waters. There is
some report of a Salamander, who lives in the Fire; but it being not
certainly known, deserves not our speculation. And, as in my opinion,
all animal Creatures require Respiration, so I do verily believe, that
also all other kinds of Creatures, besides animals, have some certain
manner of imbreathing and transpiring, _viz._ Vegetables, Minerals,
and Elements, although not after the same way as Animals, yet in a
way peculiar and proper to the nature of their own kind. For example:
Take away the earth from Vegetables, and they will die, as being, in
my opinion, stifled or smothered, in the same manner, as when the Air
is taken away from some Animals. Also, take Minerals out of the bowels
of the Earth, and though we cannot say, they die, or are dead, because
we have not as yet found out the alterative motions of Minerals, as
well as of Vegetables, or Animals, yet we know that they are dead from
production and increase, for not any Metal increases being out of the
Earth. And as for Elements, it is manifest that Fire will die for want
of vent; but the rest of the Elements, if we could come to know the
matter, manner, and ways of their Vital Breathing, we might kill or
revive them as we do Fire. And therefore all Creatures, to my Reason,
require a certain matter and manner of inspiration and expiration,
which is nothing else but an adjoyning and disjoyning of parts to and
from parts; for not any natural part or creature can subsist single,
and by it self, but requires assistance from others, as this, and the
rest of my opinions in Natural Philosophy, desire the assistance of
your favour, or else they will die, to the grief of,
Madam,
_Your faithful Friend_
_and Servant._