1910.] Action of South African Boxwood. 299 
The sleepiness, weakness, and difficulty in respiration occur in man not 
constantly but only occasionally ; were these symptoms constant in all cases 
of poisoning it would be necessary to associate them with the specific action 
of boxwood, but as they occur only occasionally it is more difficult to associate 
the action of the boxwood alkaloid after absorption with them. Moreover, 
by far the most important and characteristic early effect of poisoning by 
boxwood is the increase in reflexes; these, so far as I am aware, have never 
been recorded in man. | 
The fact that some practitioners have surmised that the symptoms may be 
due to cardiac failure is of little significance, since no reliable records on the 
activity of the heart are available, and of course to attempt to gauge the 
activity or output of the heart by feeling a peripheral artery or by ausculta- 
tion of the chest is courting disaster. 
Supposing the wood to contain 0:06 or 0:07 per cent. of alkaloid, and it 
being known that 8 milligrammes is sufficient to cause decided specific effects 
in the cat, an amount corresponding to 10 grammes of the wood, then on this 
basis a man should require to absorb the alkaloid from 800 grammes of wood 
to effect poisoning. It must be remembered, however, that whilst the amount 
of an alkaloid necessary to affect the heart varies in different mammals very 
accurately with the body weight, the same is not true for the central nervous 
system. For example, cocaine, a drug acting on the brain and causing 
convulsions, must be given to animals (frogs, rabbits, dogs, monkeys, etc.) 
in doses almost exactly inversely to their body weight in proportion to the 
relative weights of their brain substances. So that, as boxwood essentially 
affects the brain, it would be more accurate to compare the weight of the cat’s 
brain with that of man in respect to their relative body weights, and then the 
larger the brain in proportion to body weight the less drug should be required 
to cause an effect. But even such an estimation would require some 
200 grammes of the wood to be absorbed before symptoms of poisoning could 
occur. Now it will be readily admitted that the absorption of the alkaloid 
from such an amount of wood by workmen engaged in the operation of 
polishing or sawing is impracticable. Furthermore it is not possible to 
absorb water-soluble alkaloid from the skin in this way, and absorption is only 
effected with difficulty when the alkaloid is rubbed into the skin with a suitable 
fatty basis which will penetrate through the sebaceous and sweat glands. So 
that absorption when it occurs must take place through the nasobuccal mucous 
membrane, and it is difficult to conceive that more alkaloid than that which 
could be obtained from a gramme of wood at the outside could be absorbed 
in this fashion. The alkaloid from three times this amount of wood taken by 
the mouth on more than one occasion was quite without effect on a healthy 
