WFAT IS A STIMULANT? 
81 
administration in even a slight excess is immediately productive 
of one or more of tlie following decidedly poisonous effects : 
1. Narcosis; 2. Inflammation of tissues (especially of tlie ali- 
mentary canal and of tlie glandular systems) ; 3. Serious 
alteration of particular secretions from their normal type. It 
is probable that the two last groups are really only varieties of 
the narcotic effect ; that is to say^ of an effect which paralyses 
especially the life of the nervous system, but which probably 
has also a direct lethal influence on the blood and on the 
tissues generally. Be this as it may, by far the most import- 
ant of the evils inflicted by the excessive administration of 
substances, moderate doses of which act as stimuli, is the 
production of narcosis; and it is just this effect which results 
from excess in the use of some very familiar and important 
articles of daily consumption, and which unfortunately is 
constantly spoken of by the mischievous misnomer of over- 
stunulation."’^ In considering the action of stimuli, therefore, 
I shall confine myself to that group of these agents which in 
large doses exchange their stimulant for narcotic properties. 
It would be a great mistake to suppose that the interest of 
the action of such substances as alcohol, chloroform, opium, 
tea, coffee, and tobacco, is only or chiefly for professional men. 
The strictly analogous principles which distinguish the physio- 
logical operation of them all are of a kind which it is really 
important for every one to understand ; for there is a sort of 
impression abroad that, while tea and coffee are agents which 
we may afford to use carelessly, as having no very marked 
remedial effects, and no poisonous effects at all, the other 
substances which I have named are dangerous medicine 
poisons which we only admit to our ordinary dietary by a 
sort of compromise with our physiological conscience. It is 
precisely such mistakes as this which are rectified, with the 
happiest effect, as soon as we come to apply exact investigation. 
The simple observation of the comparative effects of variations 
of d'Osctge, in the two cases, at once destroys the supposed 
distinction, and places all these agents on a physiological level. 
It demonstrates that, in moderate quantities, they are stimulant; 
in excess, narcotic — paralysing to the nervous system. 
The sort of effect that is to be expected from the use 
of stimulant doses of any of these substances is indicated 
above, and the only one of the group which we are justified 
in employing in larger (that is, in narcotic) doses is chloro- 
form. Owing to an admirable combination of qualities, by 
which this drug is at once very easily received into the blood 
through the lungs, and, on the other hand, very rapidl}^ 
expelled again as soon as its temporary purpose has been 
fulfilled, we are able to employ chloroform so as to produce 
VOL. IV. NO. XIII. G 
