326 Proceedings of Royal Society of Edinburgh. [sess. 
11.21. — 0-01 grin, morphine hydrochlorate in 1 cub. cent, water 
into left aorta. 
There gradually ensued indifference to mechanical stimuli. At 
first a slight pinch with forceps was felt, later it was not felt, 
and had gradually to he increased in severity to elicit a reaction. 
11.38. — Requires a very severe pinch to elicit a reaction. 
11.50. — Reflexes slightly exaggerated. 
12.0. — Reflexes much more exaggerated. On stimulation gives 
a tetanic kick out. 
12.20. — Still slight tetanus on stimulation, hut is rapidly be- 
coming exhausted. 
12.30. — Is now much exhausted; only gives a slight spasmodic 
twitch on stimulation. 
In such experiments the cutting off of the hlood supply to the 
cord causes much more rapid exhaustion than would otherwise 
ensue. Similar results were got with doses of 5 milligrammes. 
In the descriptions of the morphine action hitherto published it 
has always been assumed that the occurrence and sequence of the 
two stages of narcotism and tetanus are a necessary result of the 
action of the drug on the nerve cells, the explanation given being 
that morphine “first depresses” and “then stimulates” the spinal 
cord. Witkowski advances the opinion that both stages are really 
the result of paralysis. We have found, however, that the 
sequence of depression and tetanus is entirely a question of dosage, 
and of how much morphine reaches the spinal cord. As we have 
seen, an ordinary dose of the alkaloid first depresses the cord, and 
this is followed by tetanus. When a minimum narcotic dose is 
given the narcosis is not deep, but no tetanic stage ensues on the 
narcotic, and hence it is evidently necessary to give a dose of a 
certain size if we wish to get both stages. When such a dose is 
given, what happens is that the morphine is but slowly absorbed 
from the stomach or subcutaneous tissue, only a small portion reaches 
the spinal cord at first, and hence the depression; but as more 
morphine becomes absorbed, more of it comes in contact with 
nerve cells of the cord, and as a result we get tetanus. 
Tetanus, we have found, can be induced at once without any 
preliminary depression if the morphine be thrown into the circula- 
tion so as to immediately reach the cord in sufficient quantity. 
