510 POISONS : THEIR EFFECTS AND DETECTION. [§ 668. 
the influence of liquor, and the paralysis of the legs increased. Forty 
minutes after the bite, he began to moan and shake his head from side 
to side, and the pulse and respirations were somewhat accelerated ; 
but he was still able to answer questions, and seemed conscious. There 
was no paralysis of the arms. The breathing became slower and slower, 
and at length ceased one hour and ten minutes after the bite, the heart 
beating for about one minute after the respiration had stopped. 
There is often very little sign of external injury, merely a scratch or 
puncture being apparent; but the areolar tissue lying beneath is of a 
purple colour, and infiltrated with a large quantity of coagulable, purple, 
blood-like fluid. In addition, the whole of the neighbouring vessels are 
intensely injected, the injection gradually diminishing as the site of the 
poisoned part is receded from, so that a bright scarlet ring surrounds a 
purple area, and this in its turn fades into the normal colour of the 
neighbouring tissues. At the margin is also a purple blood-like fluid, 
replaced by a pinkish serum, which may often be traced up in the 
tissues surrounding the vessels that convey the poison to the system, 
and may extend a considerable distance. These appearances are to be 
accounted for in great part by the irritant properties of the cobra 
venom. The local hypersemia and the local pain are the first symptoms. 
In man there follows an interval (which may b§ so short as a few minutes, 
or so long as four hours) before any fresh symptoms appear ; the 
average duration of the interval is, according to Dr Wall, about an 
hour. When once the symptoms are developed, then the course is 
rapid, and, as in the case quoted, a feeling like that of intoxication is 
first produced, and then loss of power over the legs. This is followed 
by a loss of power over the speech, over swallowing, and the movement 
of the lips ; the tongue becomes motionless, and hangs out of the 
mouth ; the saliva is secreted in large quantities, and runs down the 
face, the patient being equally unable to swallow it or to eject it; and 
the glosso-pharyngeal paralysis is complete. 
§ 668. Cobra Antitoxin. —All the so-called antidotes, such as gold 
chloride, potassic permanganate, and others, have proved to be useless ; 
for, although chemical agencies may make the poison clinging to the 
wound inert, such reagents fail to neutralise the absorbed poison. It 
had long been known that animals dosed subcutaneously by quantities 
of cobra or other snake venom, insufficient to kill, acquired a certain 
degree of immunity against the same poison ; this induced Calmette to 
endeavour to obtain an anti-venom serum on the same principle, as to 
preparation, as the well-known commercial antitoxin for diphtheria. In 
this Calmette, working in the Lille Institute, has been to a great 
extent successful. Horses and donkeys are the animals selected to 
produce the immunising and curative serum ; these animals are injected 
with ever-increasing doses of cobra poison, until thev bear without 
