New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1894-05-21
SUNSHINE IND MICROBES.

From mans earliest ages light has been re-
rardcd rs symbol of good AMI ~ life. ana
darkness ~ a symbol of evil anl 81 death.
Great systems of religion have been based upon
this principle and almost every one shows som"
clear traces Of IT'S Influence sun worship ana
so-callcd sun.myihs seem wcllnigh universal
But n has been reserved for modern science
fo vindicatc the authenticity of those myths. and
10 crystalline into tangible AMI practical form
the vast theories M which ancient sages could
only vaguely grasp and which they could "N-
press only In parallels. Light and darkness
are now seen 10 be- not merely symbols. but
potcnt agencies of life and death of good AMI
evil: If indeed they be- not the very things them
selves An essay oh This subject 10y Professor
Farmland in The Nineteenth Century gives
a sihgulariy striking view ~ som" recent In
ycsligalions into the influence ~ sunlight upon
bacteria AMI suggests possibilities of fuiur"
knowledge and achievement 81 almost meal
culablc hcnchccncc 80 mankind
The common notion that the rays ~ The sun
promote the multiplication ~ bacteria and con
scqucntly. fermentation. puircfaciion ana de-
composition. H. r. appears. incorrect. CA tn"
contrary. sunlight has lcihnl effect upon bac-
terra. especially when acting In conjunction
with the oxygen Of the atmosphere Liquids
that become tainted or Torment in The dark re-
main entirely sound and sweet IN direct sun
light Two German scientists recently spent Il
whole night from sunset so sunrise. on the bank
Of the Iscr near Munich Every hour they
dipped up some of The wafer Of the river and
ascertanol the number Of bacilli in Il drop.
Early I'm the evening there were only a few
eight or ten in drop. But they steadily in
creased In number until just before II began
to grow light AT morning they were most numcr-
ous -pcrhaps thirty in drop With the return
Of sunlight their numbers began 10 diminish
and continued 80 do so all through the day.
It had already been observed that in certain
English rivers bacill were about three times
as numerous In winter when days are short
and often dark and cloudy as in summer
when days are long and sunshine more pre-
walls
Not only does sunlight thus destroy or Al least
check the multiplication of heterogeneous, but
II II especially baneful TO those which are nox
iolIs 10 human or animal life; and when it does
not actually destroy them 1t has the cxtraor
binary effect Of radically changing their nature
so rs to make them innocuous or even actually
bcnignant. The deadly anthrax baci are
killed outright by exposure 10 sunlight in nor
posed the bacilli Of Aslatic cholera 10 sunlight
for three or four hours. Finding them still
alive, he administered them 10 n guinca-pig At
the same time lac administered TO another
guinea-plg other similar germs which had been
kept an equal time in the dark, The latter
animal died Of Asalc cholera in about egh
teen hours But the former charged with the
sun-curcd bacilli. remained perfectly well Not
hal itt
from the disease so that subsequent inocula
tons and dosings with the most virulcnt cho
era microbes had no effect upon II. Exposure
TO the suns rays had thus not only dcstroyc
the disease producing powers Of the microbes,
but had made them active and efficient agents
for resisting the noxious attacks Of their still
vrulcnt brethren.
II was. furthermore, observed that varying
effects were produced by the varying rays Of
the spectrum The red rays had almost no Of
feet and the orange and yellow only a little.
The green was more potent the blue still more
so. the effect increasing as the color decpcngl
into indigo; and the violet and ultraviolet rays
were by far the most deadly Of all. This order,
| it will be observed is Identical with that Of the
effect Of the spectral rays upon Photographic
| plate 1t Is thus the aclnic properties OF light
which have power to dcNroy or 10 transform
| bacteria. The greater the proportion Of oxygen
in the air. also, the greater Is the potency OF
| light. while IN a vacuum or partial vacuum 1t
| Is much diminished. Processes Of oxidation
| therefore. seem to have something 70 do with
the result. Light is potent TO act through and
in clear water, but that potency Is vastly in
| creased by the addition Of little common salt;
a phenomenon which may with interest be CON-