LECTURES ON CHEMISTRY. 757 
laws obtain in it, although they are under the control of the 
higher principle of vitality, designated life. 
Sir J. Herschel has said, “The science of chemistry, ” to a 
division of which it is my intention to direct your inquiries, 
“ is full of the greatest beauties, and ranks second to none of 
the sciences in value. Like them, it had its origin in human 
weakness, folly, and even absurdity. Its beginnings were feeble, 
nay, almost contemptible ; and the discoveries of its truths were 
only made through a lengthened series of mistakes and failures. 
But it has long since disencumbered itself of the trammels which 
bound it, and, having become an experimental science, it now 
rests only upon facts. Speculations are discarded, and de- 
monstrative proofs alone accepted ; hence it is placed among the 
exact sciences, being a science of number, weight, and measure ; 
while it has effected more good for mankind, taken in their rela- 
tive situations, than any other branch of natural philosophy : 
nor is there a physical science which does not receive some 
assistance from it.” 
The object of chemistry is the investigation of the laws which 
govern the constitution of bodies — the properties of the elements 
which make up the mass, the integrity of which is maintained 
by a force opposed to chemical action — the explanation of the 
changes which take place when substances dissimilar in their 
nature are brought together, and by which their mutual decom- 
position is effected and new compounds are formed ; — and, lastly, 
the resolving of a compound body into its constituents. 
The phenomena which attend chemical action are oftentimes 
wonderful, and sometimes inexplicable. Masses of matter may 
remain together sluggish and inert until the chemical affinities 
are exerted, when, all at once, the most violent and unexpected 
action is produced, often alarming the incautious, and which 
has been compared to spirits evoked by the spell of the magician. 
The result is the formation of compounds altogether dissimilar 
from the substances thus operated upon. 
At other times we perceive no visible effects. Silently and 
unseen the process goes on, but the result is the same. Some 
new principle has been evolved which may be rendered use- 
ful in a variety of ways, and these too numerous to mention. 
Now the immediate cause of all this is unknown, and, for aught 
we can tell, may ever remain so. It is only the effect that we 
witness. This, however, is no fault of the cultivators of the 
science of chemistry, who have comprised in their list men of 
the highest and most varied talents and industry ; but of the 
inherent complexity of the subject, and the infinite multitude of 
