LECTURES ON CHEMISTRY. 
755 
alone their explanation by a reference to chemical laws. There 
may be many of the processes in the arts which will also call 
forth some comments. I do so, because I- am decidedly of 
opinion that, as professional men, you ought not to be ignorant 
of these things; and I am sure you will estimate their worth in 
after-life. 
In the second part of my course, I shall introduce to your 
notice the various compounds derived either from the organic or 
inorganic kingdoms of nature, and also those that are formed by 
art, which being employed as therapeutic agents, become, in the 
hands of the educated and scientific man, means to alleviate some 
“ of the ills that flesh is heir to.” I have been, during a some- 
what lengthened period of probation, conversant with some at 
least of the wants and general feelings of veterinary students ; 
and I cannot use sufficiently strong terms to condemn the prac- 
tice of those idlers — those drones in the hive — who declaim 
against the acquirement of general knowledge, which they do on 
the grounds (as they say) that it will be of no use to them in 
their professional avocation. 
Surely such persons never gave themselves the trouble to 
think for a moment upon the subject. They have never reflected 
on what must be the necessary consequence of ignorance of those 
things, which, if they do not bear directly, do so indirectly upon 
the profession of which they are, or hope to be, members. They 
can never have asked themselves the question. Are we likely to 
be proficients in any one science without some acquaintance with 
the collateral sciences ? This may be accepted as an axiom, — 
there is not a science that can be said to be isolated. Each, 
as it were, holds the other by the hand, and thus they contribute 
mutually to assist each other. For instance, I would ask, 
How can the beautiful and intricate mechanism of the animal 
frame, with its multiplied pulleys and levers, be understood 
without some acquaintance with mechanics ] Do not the laws 
of optics afford us aid in comprehending the function of that 
admirable apparatus the organ of vision] Nor are those of 
acoustics at all less necessary in our investigation of the working 
of that beautiful machinery which Nature has enclosed in rock- 
work, constituting the internal ear; by which we listen to the 
counsels of a friend, or are warned of the intentions of an enemy. 
Again ; the principles of pneumatics are in operation every time 
we breathe, and those of hydraulics in the circulation of the 
blood ; so that of these divisions of natural philosophy the 
medical student should not be ignorant, since the healing art, 
more than any other, calls forth the energies of the ever active 
mind. I do not hesitate to say that the information of the 
