_Wherein the function of respiration ceases, while the heart continues
to circulate black blood._
It has been stated that in cases of suffocation the heart continues to
contract for a short period, after the cessation of breathing; that this
interval is extremely short, but liable to vary from several causes; and
that it is uniformly shorter in cases of death by drowning, than in
those by strangulation. To the physician this is an interval of anxiety
and importance; let him beware how he trifles with the fleeting moments,
in which alone the resources of his art can be of any avail. If
artificial respiration be established at this period, the blood will
become once more oxygenised, the action of the heart will be continued,
the scarlet blood will be transmitted to the brain, and sensibility will
therefore return; the nervous energy will be once more transmitted to
the respiratory organs, and the animal will at length make a voluntary
effort to inspire air. Here then is the interval of time, during which
artificial breathing may be employed so as to effect a restoration to
life, where death must otherwise have been inevitable. Mr. _Brodie_ has
made a great variety of interesting experiments upon this subject, from
which may be deduced the following important corollaries.