340 poisons : their effects and detection. [§ 402. 
§ 402. Physiological Action. —The tetanic convulsions are essentially 
reflex, and to be ascribed to a central origin ; the normal reflex sensi¬ 
bility is exaggerated and unnaturally extended. If the ischiatic plexus 
supplying the one leg of an animal is cut through, that leg takes no 
part in the general convulsions ; but if the artery of the leg alone is tied, 
then the leg suffers from the muscular spasm, as well as the limbs in 
which the circulation is unrestrained. In an experiment by Sir B. W. 
Richardson, a healthy dog was killed, and, as soon as practicable, a 
solution of strychnine was injected through the systemic vessels by 
the aorta—the whole body became at once stiff and rigid as a board. 
These facts point unmistakably to the spinal marrow as the seat of the 
toxic influence. Strychnine is, par excellence, a spinal poison. On 
physiological grounds the grey substance of the cord is considered to 
have an inhibitory action upon reflex sensibility, and this inhibitory 
power is paralysed by strychnine. The spinal cord, it would appear, 
has the power of collecting strychnine from the circulation and storing 
it up in its structured- 
Much light has been thrown upon the cause of death by Richet’s 
experiments. 2 It would seem that, in some cases, death takes place by 
a suffocation as complete as in drowning, the chest and diaphragm being 
immovable, and the nervous respiratory centres exhausted. In such a 
case, immediate death would be averted by a tracheal tube, by the aid 
of which artificial respiration might be carried on ; but there is another 
asphyxia due to the enormous interstitial combustion carried on by 
muscles violently tetanised. “ If,” says Richet, “ after having injected 
into a dog a mortal dose of strychnine, and employed artificial respira¬ 
tion according to the classic method twenty or thirty times a minute, 
the animal dies (sometimes at the end of ten minutes, and in every case 
at the end of an hour or two), and during life the arterial blood is 
examined, it will be ascertained that it is black, absolutely like venous 
blood.” 
This view is also supported by the considerable rise of temperature 
noticed : the blood is excessively poor in oxygen, and loaded with carbon 
dioxide. That this state of the blood is produced by tetanus, is proved 
by the fact that an animal poisoned by strychnine, and then injected 
subcutaneously with curare in quantity just sufficient to paralyse the 
muscular system, does not exhibit these phenomena. By the aid of 
artificial respiration, together with the administration of curare, an 
animal may live after a prodigious dose of strychnine. 
Meyer 3 has investigated carefully the action of strychnine on the 
blood-pressure—through a strong excitement of the vaso-motor centre, 
the arteries are narrowed in calibre, and the blood-pressure much 
1 R. W. Lovett, Journ. Physiol., ix. 99-111. 2 Op. cit. 
J Wiener Akad. Silzungsber., 1871. 
