LECTURE ON CHEMISTRY. 
69 
unwary, and the only means that we have of detecting them is by 
appealing to the principles of chemistry. Thus sulphuric acid de¬ 
tects the nitrate of lead in that of silver, and the barytes in the 
carbonate of zinc—lime-water will expose the mixture of corrosive 
sublimate with calomel—the barytic salts the presence of sulphuric 
acid in the acetic acid; while melting will render evident the colour¬ 
ing matter in the mercurial ointment; and solution, the additional 
resin in the aloes. Equally easy tests may be had recourse to for the 
detection of most of the other adulterations, and this is one of the 
many reasons why chemistry should be taught in our medical schools. 
“What shall we say of the aid of chemistry as counteracting the 
effect of poisons'! Cases of poisoning do, although somewhat unfre- 
quently, occur in our practice. The poisonous effects of corrosive 
sublimate may be counteracted by the exhibition of albumen or the 
white of eggs—the preparations of lead by the sulphate of soda, and 
of copper by sugar—of emetic tartar by astringent vegetables; and 
although we have no assured antidote for arsenic, the tritoxide of 
iron, or a solution of lime, may be tried conjoined with the free use 
of diluents. 
“ Where death has taken place in consequence of poison being 
administered accidentally, or from motives of revenge, or from the 
abominable practice of quackery, the agent can now, with almost 
certainty, be detected by ^ chemical analysis of the substances found 
in the alimentary canal.’ ” 
Our lecturer now reverted to another and most important divi¬ 
sion of his subject,—the application of chemical science to the 
phenomena of life. We regret that the limits of our Periodical 
will not enable us to follow him here. His explications on animal 
heat, respiration, digestion, and the various acts of life, were beau¬ 
tifully simple and satisfactory. We content ourselves with, or, 
rather, we can only find room for, his concluding observations. 
“ Allow me to repeat that, in your pursuits in after-life, the 
early study of the science of chemistry will be fraught with the 
highest advantage. It has been well remarked that learning, if 
rightly applied, makes a young man thinking, attentive, and in¬ 
dustrious—confident and wary; an old man cheerful and reserved. 
It is an ornament in prosperity, a refuge in adversity, and an 
entertainment at all times. It cheers in solitude, and, in the lan¬ 
guage of Bacon, is 'power. 
“ Each age should be progressive in knowledge. From you will 
be expected more than from those who have gone before you. 
You have had not only greater privileges than they, but there is the 
benefit derivable from their experience. It has been well observed 
by Sir John F. W. Herschel, that ‘ there is scarcely nny well-in- 
formed person, Avho, if he has but llie will, has not also the power to 
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