EDITORIAL OBSERVATIONS. 655 
runs its ordinary course, and when arrested, often passes 
into consumption. 
7. Hereditary diseases are less effectually treated by 
ordinary remedies than other diseases. Thus, although an 
attack of phthisis, rheumatism, or constitutional ophthalmia, 
may be subdued, and the patient put out of pain and danger , 
the tendency to the disease w r ill still remain, and be greatly 
aggravated by each attack. 
8. Hereditary diseases do not necessarily show themselves 
at birth. In horses and cattle there are only a few which 
do so.” 
The foregoing recognised results of experience make us 
acquainted with certain modes of action or operation observed 
by nature in the construction and w orking of that w onderful 
organism — an animal body. Certain data yield certain 
products, modified by a variety of circumstances of which 
we record many for the most part extrinsic; but how or in 
what manner such natural operations are physiologically 
accomplished, though we may on occasions elicit how r it hap- 
pens that they become modified or altered, must probably 
for ever remain what, to our finite understandings, is — a 
mystery. Nature’s grand and leading principle of action, 
as manifested in her wonderful works in these matters is, 
that like issues out of like. You cannot gather figs from thistles, 
no more than you can expect a horse to produce a cow, or a 
man anything but a human being; but how the specific orga- 
nisation itself is varied, or how it specifically acts in each 
generic class to reproduce its kind, and nothing but its kind, 
is, it appears, more than w r e shall ever approach any know- 
ledge of nearer than the possession of a few scattered facts, 
w hich, after all, lead us but a short way into the labyrinth of 
Nature’s impenetrable secrets. 
Touching the hereditary transmission of disease, Mr. Dun 
views it as “the same as the superinduction of spavin or curb 
in hocks of certain construction, also depending upon the 
altered conformation or texture of the, parts specifically affected, 
or upon some disturbance of the relation which should subsist 
between the different constituents of these parts;” or,w r e would 
