192 ANALYTIC PHYSIOLOGY. 
and though subsequent authors have loudly as- 
sailed it with hard names, yet it still remains 
unshaken; but there is a wide difference be- 
tween censure and argument, As Cullen’s work 
is in every one’s hands, I shall enter into no 
detail of the facts on which his theory is esta- 
blished; but, supposing it to be true, that the 
cold stage of an Ague proceeds from diminution 
of the Vital Force, it is obyious, that by raising 
it effectually before the accession of the fit, all 
the symptoms of the cold stage should be ar- 
rested. It was from a deep impression of the 
truth of this conclusion that I recommended 
Dr. Sillar to apply externally the nitrate of silver 
in a case of Quartan Ague, which had lasted 
upwards of twelve months, and had resisted both 
bark and arsenic. 'The eschar was made an hour 
before the accession of the paroxysm; we re- 
turned to see the patient at the period when the 
cold stage usually ended, but it had not come 
on; our entrance roused him from a comfortable 
sleep. It would be superfluous to descant here on 
this synthetic proof of Cullen’s theory; I leave 
it for the discussion of the contending theorists of 
the present day. 
‘Bark is usually so far successful in the cure of 
Intermittents, that any proposal to supersede its 
administration, would most justly merit severe 
reprehension ; but, now and then, it either fails, 
