Evening star., 1894-03-20

arsenic was taken up at this point as the
most common and the best known, as well
as, perhaps. the most harmful of these
poisonous coloring agents This substance
said the lecturer, may occur in either of
these ways, being used as a pigment also
nhdlns ulrect employment in The produc-
tloh OF organic coloring matter and as a
mordant IN dyeing. 1t is quite cheap i'm The
form OF the sublimate, and this cheanness
combined with the brllliancy and durability
Vi the coiors OF Its compounds, are the
factors that determine its wide use as a
pigment for wall paper. The arsenical
greens are Scheele's, Schweinfurt's and
faris greens. are all used widely, and are
az. aii ueaIy 1y polsons, differing in intensity
Out snghtly from the pure element One
manufacturer of wall papers alone used
TWO tons OF arsenic weekly, while the entire
product OF arsenic from England was only
from 90 TO 400 tons year
While the green's" Prof Munro uap,
on are those among the arsenical colors
that nave been most generally used for
uecoratihg wall papers, yet it must not he
inferred that the presence of a green color
is necessarily due to arsenical compounds
Ior there are many other green matters
employed in painting, dyeing and coIorin y
.nat are wholly or comparatively innocu-
GUS on the other hand, ii is equally erro-
neous TO suppose that the absence Of n
green color proves the absence of arsenic
from paper, for the arsenous oxide real
gar, orprnent and mineral blue possess
respectively, brilliant white, red yellow
and blue colors that are used in wall mn .
pers, either alone or in mixtures In fact
there is no positive assurance of the ab-
sence or presence of arsenic 10 he had ax
cept as proved by a careful chemical anaIy-
Sis. There can be no doubt that rhere is
grave danger to be apprehended from the
use OF arsenical papers. and the poisoning
to,,so 80 inslulous ana stimulates in its symp-
TOMS SO many other forms of disease as 70
palne the physician who does not resort 10
the method of analyzing the urine
mere are two theories as to how the
poisonous matter becomes detached frn,,
the papers and sent to the victim. Iba -.
theory and the volatilizat ton theory r.
fore considering them, however Prof MIIn-
roe went on to describe the processes of tho
manufacture of colored wall papers TO in
dicate that the pigments are laid on y.;,h
size whlch dries and thus holds the poison
substances by very slight grin Then ba
plocesoed: Inc arsenfcal paper hangings
include three well-defined varieties accord
ing TO the methods used to attach the color-
ing matter to the surface of the naner ,,-i,h
greater or less permanency; they being
s sSieu u!siaZed, satined or flock. 1t is evi-
dent that this coloring matter NAV he re
moved through abrasion and thrown os
dust INTO the atmosphere when II xould ha
lhhaied' but of all the varieties named
those papers having an unglazed surfa 90
are most likely TO produce harm. since ~
color Is only moderately adhesive and is
removed by the slightest friction. Next in
glazed. Vi al the
The dust theory holds that the no;so,
ing Is effected by the inhalatio of narticlas
OF arsenical dust which have been sens ~ .
ed IRON the paper and dissemina ted
through the atmosphere. Up to tho as,
TWO years this has been the generalIv ac
cepted theory. 1t is well known thar in the
least used rooms dust abounds in the air 70
SO great an extent that a beam of SUNLIGHT
reveals cloud of flying particles of uncer>
tam origin. chemical analysis of tho
uust from furniture and mantels of arsenic
pdtered rooms, even that which had nene-
trated through the glazed doors OF hool
cases, has given the Characteristic reoc-
tions Tor arsenic. Yet complete as This
theory seems to be. II yet fails to exolain
an OF the instances of chronic arsenicaI /
poisoning that have arisen from paper
hangings" paper
The Theory Of VolatiIiznttou.
Ihe lecturer then vert CT to exnlafn the
other theory. that of volatilization aII,,d-
ing to the bad practice If -spapering rooms
without removing the old paper first. ..pv-
ing to this state Of Affairs" he said ..it
mas been found that cases of chronic ar
senlcal poisoning have occurred in person g
occupying rooms in which the exposed IA
per was free from arsenic, hut the under
lying, and apparently protected paper was
arsenical, yet evidently the dust theory
fails in this case to explain how the arsenic
was brought into the atmosphere. Again
II has been observed that the atmosphere
of rooms hung with arsenical paper, which
had been closed for some time. was in
certain conditions of the atmosphere, per-
vaded with the garlic odor characteristic of
certain volatile compounds of arsenic. but
which does not obtain with the solid color