CINCHONA OFFICINALIS. 157 
tioners, of seeking in previously-formed opinions, in hypotheses 
founded on fancy, in theoretical propositions, and in casual 
effects, that, which in an experimental science should be sought 
in unbiassed trials, and observations made with extreme care. 
“‘T propose these last means, in order to avoid conjecture and 
traditional opinions that have not passed through the ordeal of 
experience; and, with regard to China, I have proved that 
although it is a certain remedy in many cases, it nevertheless 
causes in persons in health morbid symptoms, frequently very 
violent, and of long duration. 
“This is sufficient to refute the received opinion that China 
is never injurious, and perfectly innocent, and that it acts only 
as a remedy. 
“ Tt is not less certain, agreeably to its morbid effects on per- 
sons in good health, that its frequent failure, when used by 
common practitioners, and the aggravation caused by repeated 
strong doses in many diseases, which are at length rendered 
incurable by it, are owing entirely to the mischievous mistake 
of giving it in cases to which it is not applicable, and in large 
doses; and this is always gratuitously ascribed to aggravation 
of the natural disease taking place of itself, and not the fault of 
the physician. 
“1. Quinine is one of the most powerful vegetable medicines, 
when it is employed against a disease to which it is really 
applicable, and when the subject is severely attacked by that 
disease. I find that a single drop of the tincture, so much 
diluted as to contain only the quadrillionth part of the essence 
of Quinine, is often too strong, but always powerful enough to 
perform all that this medicine can effect in such a case, and it is 
very seldom that the patient requires a second dose. Long ex- 
perience, based on the closest observation, has led me to reduce 
the dose to this extent, and it has clearly proved to me that even 
the highest dilutions exercise a more powerful action than is 
required. 
“ Thus I have proceeded, diminishing by degrees, till I should 
N 
