Introductory Lecture. 293 
the inanition of a thousand years appeared to be appeased. 
The squeamishness of satiety succeeded ; and asserted facts 
as well as doctrines began to undergo a closer scrutiny be- 
fore they could be admitted. The process of digestion had 
commenced ; and the judgment was too much occupied with 
the selection and appropriation of the solid and nutritious 
matter, to receive with complacence the same kind of hetero- 
geneous mixture which had hitherto satisfied the taste. The 
philosophy of Bacon, which rejected all theory not based upon 
and supported by facts, and admitted nothing as fact except 
upon positive evidence, began to be received as the only le- 
gitimate guide in the search after truth. Under the influence 
of these principles, antiquity ceased to be venerable ; and 
imagination was banished from science into poetry. An 
immense mass of rubbish, the accumulation of all preceding 
ages, was washed away in the operation of experimental in- 
quiry; and the particles of pure gold which had weight 
enough to withstand the current, remained to reward the la- 
bors of the search, Magic, and astral influence, and all the 
host of imaginary powers which dwell in the strange, the dis- 
gusting, and the horrible, fled with ghosts and fairies before 
the new day which broke upon the human intellect. The 
removal of the weeds and rubbish which had choaked the 
sprouting sciences, now left a clear field for their growth. 
Botany sprang rapidly from its embryo state into a flourishing 
existence ; and, in the accessions which it afforded to the 
Materia Medica, and the greater precision which it intro- 
duced into this branch of medicine, bore fruit sufficient to 
prove that it was not a mere ornament in the garden of knowl- 
edge. But it was from the wonderful improvements in 
Chemistry during the last century, particularly towards its 
close, that Materia Medica and Pharmacy experienced the 
greatest benefit. Not only were new and valuable medicinal 
compounds produced, but those already in use were rendered 
purer, and therefore more uniform in their action ; the pro- 
cesses for the preparation of medicines were simplified, and 
brought under the direction of precise rules ; certain principles 
