1889 - 90 .] Mr Dott and Dr Stockman on Morphine. 
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tetanus is that after each spasm a period of exhaustion ensues, and 
there is no further tetanus — either spontaneous or reflex — until a 
short interval has elapsed. Not only, therefore, is the spinal cord 
abnormally easily excited, but it is abnormally easily exhausted. 
A healthy frog will react to stimulation time after time in an equal 
degree and gently, while the morphinised frog gives out all its 
energy for the time being in one prolonged and exaggerated spasm. 
According to Witkowski, the apparent stimulation is in reality 
a kind of paralysis, and is simply a failure on the part of the spinal 
cord to husband and properly distribute its resources, this dis- 
arrangement resulting in an unmanageable and violent explosion of 
nerve energy. Hence it requires a rest until more is stored up. 
We have observed, however, that the smaller the dose by which 
tetanus is induced, the less marked is the tendency to exhaustion, 
and if the animal survive a few days this tendency to exhaustion 
after each spasm wears off, and the tetanic attacks cannot be dis- 
tinguished from those of strychnine. 
Smaller doses cause only narcosis and depression, followed, 
generally on next day or earlier, by a marked increase in the reflex 
excitability, not amounting to tetanus. Very small doses simply 
cause slight narcosis. 
That small doses of morphine depress the reflex and conducting 
powers of the spinal cord can be shown without much difficulty. 
Meihuizen, using decapitated frogs (Tiirck’s method), found that 
there was depression, followed by increase of reflexes. This has 
been confirmed by Witkowski and by ourselves in many experi- 
ments. To confirm these results obtained by Tiirck’s method, we 
administered morphine to decapitated frogs, and found that, although 
in many cases the spinal reflexes were very slightly depressed, yet 
in others the depression was extremely marked, and was succeeded 
in due time by tetanus. As in these cases the brain was removed, 
the primary depression and subsequent tetanus must have been quite 
independent of it, and due solely to an action on the cord. Moreover, 
small doses of morphine directly injected into the aorta of decapi- 
tated frogs (so as to make the results independent of irregularities 
in absorption from the stomach or subcutaneous tissue) gave similar 
results. Thus — 
Expt. 1. — Frog pithed; right aorta tied. 
