INTRODUCTORY LECTURE. 
273 
it, capable of sustaining tons in weight; and the steam engine 
itself, that mighty agent, giving to man the power of a giant, 
was incomplete, and would probably have been abandoned, 
had not the genius of Watt applied the means of suddenly 
depriving the steam of all its expansive power, by the adop- 
tion of a simple contrivance, to which he was directed by a 
knowledge of the fact, that this expansive power was due 
to the latent heat within it, as likewise discovered and taught 
by the celebrated Black, Professor of Chemistry at Edinburg. 
Who that has enjoyed the security and comfort derived 
from the brilliantly illuminated streets of a city, when he is 
told that the production of the elastic fluid, which is consumed 
to afford the lamp that lights his path, could never have been 
accomplished without the aid of chemistry, can withhold 
from that science the character which I claim for her, of being 
intimately connected with domestic comfort and happiness? 
The consideration and examination of all these facts, is 
calculated to show the importance of a knowledge of chemistry 
in promoting, and creating a thousand conveniences, which 
characterize civilized society, and of winning for her devotees 
the respect and veneration of all who are made acquainted 
with her advantages and allurements. But when applied to the 
relief of suffering humanity, exhausted on the bed of sickness, 
or prostrate from the maddening influence of pain, bereft of 
reason, through disease, or burning with the heats of fever, 
then, indeed, is chemistry a ministering angel. 
Who that has enjoyed the delights of calm repose, obtained 
through the aid of anodynes, after days and nights of sleepless 
wretchedness; who that has allayed the parching thirst of 
fever, and experienced the relief afforded by the effervescing 
draught, has ever dreamed of awarding to chemistry her full 
share of credit for the relief thus opportunely obtained? 
It is by recounting some of these facts, and apprising you of 
their existence, that I trust to be enabled to show you how great 
have been the contributions of chemical science to the supply 
of your different wants, and the alleviation of your sufferings, 
and to convince you how essential is a knowledge of its 
