this Volume, p. 35.) viz. like tar water, in some water that
I impregnated with fixed air about three years ago. I did not then know
to what to attribute it, but your experiment seems to clear it up. I
happened to have spent all my acid for raising effervescence, and to
supply its place I used a bottle of dulcified spirit of nitre, which I
knew was greatly under-saturated with spirit of wine; from which, as
analogous to your observation, I imagine the effect proceeded.

As[24] to the coagulation of the blood of animals by fixed Air, I fear
it will scarce stand the test of experiment, as I this day gave it, I
think, a fair trial, in the following manner.

A young healthy man, at 20 years old, received a contusion by a fall,
was instantly carried to a neighbouring surgeon, and, at my request,
bled in the following manner.

I inserted a glass funnel into the neck of a large clear phial about oz.
x. contents, and bled him into it to about oz. viii. By these means the
blood was exposed to the air as little a time as possible, as it flowed
into the bottle as it came from the orifice.

As soon as the quantity proposed was drawn, the bottle was carefully
corked, and brought to me. It was then quite fluid, nor was there the
least separation of its parts.

On the surface of this I conveyed several streams of fixed air (having
first placed the bottle with the blood in a bowl of water, heated as
nearly to the human heat as possible) from the mixture of the vitriolic
acid and lixiv. tartar, which I use preferably to other alkalines, as
being (as Dr. Cullen observes) in the mildest state, and therefore most
likely to generate most air.

I shook the phial often, and threw many streams of air on the blood, as
I have often practised with success for impregnating water; but could
not perceive the smallest signs of coagulation, although it stood in an
atmosphere of fixed air 20 minutes or more. I then uncorked the bottles,
and poured off about oz. ii to which I added about 6 or 7 gtts of spirit
of vitriol, which coagulated it immediately. I set the remainder in a
cold place and it coagulated, as near as I could judge, in the same time
that blood would have done newly drawn from the vein.

P. 82. Perhaps the circumilance of putrid vegetables yielding all fixed
and no inflammable air may be the causes of their proving so antiseptic,
even when putrid, as appears by Mr. Alexander's Experiments.

P. 86. Perhaps the putrid air continual