Year: 1873

tongue of ninety-nine out Of every hun
dred persons who may read or hear the
question that heads this article. But how
do sudden changes of temperature give us
cold Z? Too sudden contraction of the
pores Of the skin; sudden checking Of the
sensible or insensible perspiration, sudden
change of circulation by which the blood
is thrown, from the surface inward, upon
the vitals, causing congestion, etc, All
these are phenomena which may, some or
all Of them, be connected with too sudden
or too great changes Of temperature, but
when all taken together, of accounting for
that very ordinary, very amazing, and too
often seriously injurious affliction, bad
cold


Few of us but what can count scores of
instances in which we have been exposed
to very sudden and very great changes of
temperature, from warm to cold, without
other inconvenience than an uneomforta-
Bile chill, while We can also count many
instances in which We have taken very
severe colds without being able to tell how
or where We come by them The slight
and almost imperceptible, frequently un-
observed, causes of cold have not, perhaps,
been as closely traced as they should and
may be- 1t seems not so much the change
as the kind of change which gives rise to
the unpleasant result The leaving off of
an accustomed garment, even when the
lack is not uneomfortably felt, the expos
ure Of the feet TO wet or chill, few min.
utes with the head uncovered in the cool
outdoor air, but above all, exposure to a
draft of air, especially, as is generally be-
lieyed, on the back of the head or neck,
are all familiar examples, of which most Of
us have had melancholy experience. OF
the last--the draft upon the back of the
head or ncck-the danger is proverbial.
Witness the proverb, Spanish we believe
it is originally: "If the cold wind reach
you through hole, 60 make your will and
mend your soul Or the Persian male
dietion: MAY cold wind blow in the
back of your neck !"


Indeed there seems to be, especially to
peculiarly sensitive constitutions, almost a
certainty of cold in such currents of air.
There may be no chill, not even uneom-
Portable coolness, and yet the symtcms OF
a cold manifest themselves almost as sud.
denly and fully as decidedly as sneezing
follows the introduction of some irritating
substance, snuff, for instance, into the
nostrils. BY Immediately needing the
warning Of the first premonitory sneeze,
and at once changing the position of things
so as to avoid the cause, the cold may be,
and often is ayerted But the danger is
that the cause, being so slight and coupled
with so little present annoyance, is apt to
pass unnoticed or disegarded until too
late.


We have all, at some time, experienced
in ourselves exceptionally sensitive condi-
tiOns under which it seemed impossible for
us to avoid, as it is said sometimes "taking
one cold on the top of another" what a
gentleman not long since, in the presence
of the writer, called summer cold" in
which one seems to take the more cold the
warmer he is: it is sort of sweating cold,
one of the most disagreeable if not the
most dangerous class of these infections.
lnthis condition, the slightest draft sets one
to sneezing, and it seems impossible to
avoid constant accessions to the malady.


But why? The sudden change of tenn
perature theory will certainly not explain
those eases where it is hardly possible to
preserve temperature sufficiently even to
prevent taking cola, and those cases where
cold is taken unconsciously. No hypoth-
esis but that of direct irritant acting
upon the mucous surfaces of the lungs and
air passages seems to suffice for the phe-
nomena Of certain class Of colds. That
there is such an irritant in the air, in
quantities varying according to the mete-
geological conditions, is well known but
all its properties and effects are not vet
perhaps fully understood.


That ozone is such all irritant is a well
understood fact but to what extent colds.
in the head, throat and lungs, are due to
its agency is an open question.


NJ. Houzeau, describing in Les Mondes
process for the instantaneous oxidation
of pure alcohol, in which process ozone is
the principal agent, says in conclusion :
Il cannot too strongly recommend the
greatest caution to chemists in the use of
concentrated ozone inhaled, even in small
quantities, ii occasions suddenly an nfam-
nation of the mucous membranes, which,
as | have had occasion 10 witness, may
cause splitting of blood Such being the
undoubted effect of concentrated ozone, it
is certainly plausible theory, to say the
least, that currents Of air containing this
substance in unusual quantity, may cause
such an irritation to greater or less de-
gree, and thus be the cause of colds. In
support of this theory is the fact, well
known to physicians, that colds are fire.
quently almost epidemic when there is no
remarkable change in the weather, while
again very great changesfnay be compar-
atively unattended by them. Said an ex-
perienced physician. "When | have one
patient afflicted with certain kind Of cold
in the head, l always expect more cases of
the same kind. Hence the term ''infu-
enza, or influence, supposed to be in the