retort, capable of holding 12 ounces of water, with an empty bladder
attached in place of a receiver, the retort also placed so that the
sulphur which rose into the neck could run back again. After all had
become cold, I found the air neither increased nor diminished: it smelt
slightly hepatic, and extinguished a burning candle. I shall prove
further on that sulphur can unite with more phlogiston; and it seems to
me to follow from this experiment that something inflammable from the
air had deposited itself upon the sulphur, and that the air had thereby
acquired the property of a vitiated air. It is, however, also remarkable
that other bodies which attract the inflammable substance more strongly,
as for example, the fuming acid of nitre, do not abstract it from the
air. It is likewise strange that I was able to inhale the inflammable
air into my lungs only 20 times; and I observe here as something
peculiar that, if I mistake not, I became very warm a quarter of an hour
afterwards. It is also to be observed that fire-air, vitiated by the
lungs, extinguishes fire; why does not the aerial acid attract the
phlogiston again? why not also the vitiated air? Mr. Priestley indeed
has accomplished this, but it did not succeed with me however much I
also wished it. He has converted aerial acid into wholesome air by means
of a mixture of iron filings, sulphur, and some water. When I desired to
repeat this experiment, the aerial acid was always absorbed by the iron
filings. I likewise powdered finely some iron filings which had been
fused together with excess of sulphur, moistened this with water, and
preserved it in a bottle which was filled with aerial acid: but with the
same result. After 2 two days the aerial acid was almost entirely
absorbed. This philosopher also says that he has made vitiated air
wholesome again by agitation with water. I must admit, however, that
with me this likewise failed. I filled a flask one fourth part with
vitiated air, and the remainder with fresh water; I closed the flask
very tightly, and shook it up and down for almost a whole hour. Then
when I collected this air in a bladder, and from this in a bottle, I
found that the candle was extinguished afterwards as it was before. He
mixed with water, by agitation, the inflammable air from metals; this
also would not succeed with me, although I used only little inflammable
air, and much water. He also observed that plants made vitiated air
wholesome again. It follows from my experiments that they vitiate air. I
kept plants, in the dark as well as exposed to sunlight, in a flask
which was filled with vitiated air and carefully secured (which careful
securing must really be attended to). I tested a little of this air
every 2 days, and always found it vitiated.
+94.+ Water has the peculiar property of separating the proximate
constituents of air; of uniting with fire-air; and of entering into no
kind of union with vitiated air. (1.) I filled a large bottle with
boiled water which had been cooled shortly before, and permitted the
tenth part to run out. I then placed the bottle, inverted and open, in a
vessel with water. I observed the quantity of air to diminish a little
every day, and when this diminution ceased, I collected the remaining
air first in a bladder (Sec. 30, _h._), and from the bladder in a bottle (Sec.
30, _c._), and brought a burning candle into the bottle; it had scarcely
reached the mouth when it went out. (2.) I then took the same kind of
water freed from air, filled a bottle with it, and permitted the tenth
part of it to run into a bladder filled with vitiated air. I next placed
the bottle, inverted, in a vessel with water, and observed the space
which the air occupied in it. I found, 14 days afterwards, that the
water had not absorbed the smallest quantity of it. (3.) I placed a
large bottle, from which the bottom was knocked out, in a deep kettle
with water, so that the water outside reached above the top of the
bottle. I then tied a bladder, empty of air, over the top of the bottle,
and made the water boil up once over the fire. The air which was in that
portion of the water contained under the bottle rose into the bladder;
and after I had tied up the bladder, and detached it front the bottle, I
filled a phial with it, and put a small burning candle into it; it
burned there more brightly than in ordinary air.
This fire-air, dissolved in water, must be as indispensable for aquatic
animals as for those which live upon the earth. They must draw it into
their bodies, and convert it either into aerial acid or into vitiated
air. Into whichever kind it is, however, it must always become separated
from the water again, for as aerial acid it does not remain with the
water in the open air, and vitiated air cannot unite with water at all
(No. 2), the water is then in a condition again to absorb fire-air anew,
and to convey it to the animals. My experiments made with respect to
this matter agree with this entirely. I allowed a few leeches to remain
in a bottle, which was half filled with water and well closed, until
they died. I then examined the air standing over this water. It had no
smell, nor had the water; it appeared to have increased a little and it
extinguished fire. It seems that these creatures live only upon the
phlogiston in fire-air, perhaps also upon the heat. I have preserved
them alive in water, and that the same water, for two years; the bottle
was only tied over with gauze. I have a convenient method to ascertain
whether fire-air is present in water or not. I take, for example, an
ounce of it, and add to it about 4 drops of a solution of vitriol of
iron, and 2 drops of a solution of alkali of tartar which has been
somewhat diluted with water. A dark green precipitate is immediately
formed, which, however becomes yellow in a couple of minutes if the
water contains fire-air; but if the water has been boiled, and has
become cold without access of air, or if it is even a recently distilled
water, the precipitate retains its green colour, and does not become
yellow sooner than an hour afterwards, and not yellow at all if it is
protected from access of air in full bottles. I have already shown (Sec.
15) that the green precipitate of iron owes its colour to phlogiston
which still adheres to the earth, and it follows from this that
fire-air, although not in the elastic condition, is able to attract
phlogiston. The following experiment likewise shewed me that aquatic
animals take fire-air from the water. I placed a leech in a bottle which
was completely filled with water, and was protected from every kind of
air. After two days it was almost dead. I then examined the water in the
manner described above, and found that the earth of iron retained its
green colour. The swelling up of peas in cold water is to be ascribed
mainly to the fire-air present in the water. If a bottle is filled full
of water and a few peas are placed in it, after 24 hours the water
contains aerial acid it is true, but no fire-air. In water boiled and
become cold, peas swell up only a little. I perceive in this the reason
why the waters distilled from plants not only lose their smell, but why
also a mucilaginous substance settles to the bottom, when the bottles
are frequently opened, whereas the same waters, in perfectly full
bottles, retain their smell and clearness unchanged. All plants
communicate to water some mucilaginous material which is carried over
along with it. Fire-air is the chief cause of this corruption; if this
enters the water again, it attracts to itself the inflammable substance
from the subtle oily and mucilaginous matter, and alters the whole of
the water.
* * * * *
Transcriber's Note
All bold text has been surrounded by + signs. Italic text is
denoted by underscores.