The citizen. (Frederick City, Md.) 1895-1923, 1895-04-12
prepared Weekly, for the Citizen,


either of the sources-ou adding blue
light. Red aud yellow patches then
appeared of the same color. but the
difference was brought out on substi-
tuting green light for tue blue. That
the brightness of objects has much ot-
feet on color-di>proviug the idea that
definite wave length corresponds To
a definite color svn>atioH ia normal
eyes-was shown in a region of the
spectrum near the q line Of Frank
hoier's scale, where the color Is violet
when the luminosity Is feeble, blue
when ii Is stronger, aud may even APP
pear blush white in strong sunlight
Herr Nogel concludes that our esti-
mate of color is guided 10y our percep-
tion of the absence Of certain coustitu-
ents, red, for instance, being recogniz.
ed only when we perceive its inability
to reflect other rays.
The duck mole of Australia, which
Sidney Smith declared made Sir Jc-
seph Banks miserable from his utter
inability to decide whether it was "a
bird or beast, Is a mammal with web.
bed feet and ducks bill, and il L.
markable for laying eggs like bird or
reptile. II was long thought harmless
anu without defence. Or. y. Stuart
has lately found, however, that pow
erful spur of the males hind leg. APP
parently connected with gland, may
infiict horne like sting, which is
sometimes fatal to dogs.
Since Homer's time vast falls of or
ganic PARTICLES, a well as Of meteoric
dust, have been known at variuu,
times and places. DIR. /. :. Blair, of
Harrisburg, argues that the organic
matter may have largely come from
space, and that showers of still living
germs may explain the sudden appear
ance ana rapid spread of many historic
epidemics.
In the literature accessible, Maiselis
last year found recorded sos eases of
second attacks OF smallpox, and 9 of
AlitlAA dAldihS, ~ VI SNNbbh dAtdNh~ Nl
scarlet fever, and 1 of third: SO of sec
ond attacks of measles, and of third j:
202 of second attacks of typhoid fever
and ) of third; and % Of second at
tacks of cholera. aud 3 Of third Only
eases of fourth attacks OF typhoid
fever and of chulera-were discover
ed. Steruberg, in a recent paper 10
the Biological Society If Washington.
nnfaH than NNilitA H. t,r.ra..fi,,, ..ffnr.3-
ed by single attack against second
is in a considerable number of iuftc-
tious diseases generally permanent, it
is in other diseases more OF less tempe
rary and II varies not only with the
disease but with the individual, the
family and the race. IL some diseases
such rs pneumonia. Influenza aud A.
iatic cholera--it Is difficult t. deter
mine from clinical experience whether
first attack eNeit> any protection,
but experiments on The lower aulmai>
make it probable that certain de-
gree of immunity l. afforded Iu all M
fictitious due 10 bacterial parasites In
the malarlal teVer>. which are due to
bacterial parasite OF a different class,
first attack; On the contrary rather
predispOes TO a subsequent one. The
principal factor IN the production of
acquired immunity i now believed To
be the introduction into the bluod OF
So lie substance capable of ueutraliZiug
the toxic products OF the particular
pathogeuic organism 10 be resisted or
destroying the germ Itself Our
know ledge of the autitoXlno-w hIch
Go not as q rule have a germcid al ac-
ton, and otherwise differ from the
aleXins, 10 which natural immunity Is
ascrlbed-dates from 1890, when il
was discovered that the blood of All
animal immune from from anthrax
contains some substance utulrallZiug
the anthrax bacillus aud that the path
ogenic power OF viruleht haccili OF
dlphtherla and tetanus may be similar
~ neutralized by the blSod of auImals
immune from these dis,ase since
then the existence OF other autituNits
such as those Vf tuberculosis, rab.es.
typhoid fever and luiis-has teen de-
monttrated. Ia lS6l Ehtlich expert
mented with powerful t0Xaibumius-
vegetable pOisOus diff ring from those
of bateua-and found that uN subruta-
neous Injections of dilute solutions an.
mails could be made To bear dose If
200 or $40 times that ordinarily fatal,
immunity against one poison, howev-
er, having no effect AGAINST another OF
the same class. Ii was also proven in
1887 and confirmed in 1894 that AMI
mails may acquire certain immunity
from snake venom.
Results of German inquiry prove
that overhead wires tends 10 reduce the
violence of thundersl orms and lessen
the danger from lightning. Cases If
damage from lightning were about five
times as numerous in places without
telephone systems "a iu Those having
them.
Extraordinary results have been Ie-
ported from trials of new stune-cut-
ting material called "krushite.N The
substance consists of tiny metal shot,
hanging from mere powder 20 clover
seed size, which have heen chiltd Ia
intense harduess-but without pr, due
ing bntlleness. The neteri.l is sub
stiIuted for sand-equirlng no change
of machinery for SAM ing granite aud
other stone, aud is said IL be capable of
doing the work OF diamond SAWS at
tenth Of the expense. Ii is alsu effect
lively used i'm sand-Llast apparatus, aud
in place of diamond drills Tor boring
and drilling. A ton of il has teen
found Ia equal 800 tons OF sand iur saw
ing and polishing. 1t does its wolk 10y
crushing projecting Iarts over which It
rolls aud IL DOES no,-like sand, emery
m anrnndnn,-h eann.a natfiafly am.