464 LOGANTACEA, 
According to Falck the minimum lethal dose’for rabbits is 
023 gram. per kilo of body-weight. Strychnine kills 3-06 
‘times quicker, the intensity of the action of strychnine relative 
to brucine being as 1 to 117°4. (Vierteljahrsschr. f. Gerichtl. 
Med., Band. xxiii., p. 78, quoted by Blyth on Poisons.) 
The experiments of Dr. W. H. Klapp (1878) led him to 
‘conclusions which may thus be summarized: 1, Strychnine 
produces no primary lesion of the nerye-substance proper. 
2. Its convulsions are not cerebral. 38. It does not affect 
either the sensory or motor nerves at their periphery. 4. 
These nerves are unaffected by it in their course. 5. Its 
‘tetanizing effects deperd upon its action on the gray matter of 
‘the spinal cord. 6. In small doses it excites the vaso-motor 
centre. In large doses it paralyzes that centre. 8. It slows 
the pulse by an immediate action upon the excito-motor gan- 
glia of the heart. 9. It does not act on the pneumogastrics, 
but decreases the number of respiratory movements, at first 
from too little blood, and afterwards from too much blood 
flowing to the respiratory centres. 10. Artificial respiration 
always moderates the spasms, not by a reflex stimulation of 
the pneumogastrics, but by maintaining the oxygenation of 
the blood until the poison is eliminated. . 
It may, then, reasonably be believed—1, that strychnine does 
mot act upon the muscles, the nervous extremities, or the 
nerve-trunks; 2, that it does act upon the nerve-centres in 
the medulla cblongata and medulla spinalis; and, 3, that it 
acts upon those centres first by stimulating them when given 
in small doses, and by exhausting them, and thereby exagger- 
ating their reflex irritability, when poisonous doses are used, 
in this respect falling under the general law that the actions 
of small and of large doses of an active agent are antagonistic 
to one another. (Compare Poole, Med. Record, xix. 201. ) The 
latter, of the two effects is probably dependent, in part at 
least, upon the power of strychnine to contract the arteries 
and the heart and to slow the pulse. It is essentially through 
spasm, in so far as it throws the respiratory muscles into tonic - 
