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covered Pomone, which resembled a star of the 11th magnitude.
He afterward successively discovered the following: Atdlante,
Oct 5th, 1865 ; Harmonia, March 81st, 1856 ; Daphne, May 22d,
1856; iVysa, May 27th, 1857; ^^ma, July 11th, 1857 ; MeleU,
Sept. 9th, 1857; Palis, Sept 19th, 1857; Doris, id.; Europa,
Feb. 6th, 1858; Alexandra, Sept 10th, 1858; Danae, Sept 19th,
1860 ; Canope, May 9th, 1861. By reason of these discoveries
he several times received the astronomical prize from the Acad-
emy of Sciences. He also determined the position of more than
ten thousand stars which before had no place upon anv known
map of the heavens — and it was among these stars that ne found
theplanets previously enumerated.

He made these discoveries with a small glass — and his observ-
atory was situated in one of the most frequented streets of Paris.
Not favored by fortune, Gbldschmidt lived on a pension paid
him by the French government For a long time he had been
troubled with his eyes, but this affliction affected him much less

Ah. Joub. Soi.-— Sscokd Sxsixt, Vol. XLIII, No. 127.-^ak.| 1867.

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90 Carreipandence of J. NickRa.

than diabetes^ the symptoms of which he first felt in 1854. He
then retired to the country, and for three years lived at Fontain-
bleau, dividing his time between painting and astronomy. To-
ward the latter part of last August his disease became compli-
cated with other difficulties. He hastily finished his papers upon
the physical constitution of the sun, and died on the 20th of
August. He leaves a widow and two daughters without fo^
tune. They will doubtless be adopted by the '^Soci^t^ de Se-
cours Amis des Sciences."

Spectrum of aqueatis vapor. — ^We now know the nature of the
rays which Brewster discovered in 1883, and which have since
been termed telluric or atmospheric. M. Janssen has made
several investigations under the patronage of the Minister of
Public Instruction, and has found that these rays are oocasioned
by the vapor of water. By means of new optical dispositions
he has proved that the bands of Brewster were formed of fine
lines, like the lines of Fraunhofer, and that they were constant
in the spectrum, though of variable intensity according to the
height of the sun. Belying upon this character of the telluric
rays he has made a chart of the spectrum in which the distinc-
tion between the solar and telluric rays is clearly shown.

Janssen has also made numerous other experiments. In Sep-
tember, 1864, from the summit of the Faulhorn, he observed
the rays of terrestrial origin and found they became weak in
proportion as they were elevated and as the light had less thick-
ness of atmosphere to traverse. In the same year he made an
experiment upon Lake G-eneva, and by reason of the humid air
of the lake he was able to reproduce the same rays artificially.
The flame from a large pile of pine wood at the distance of 21
kilometers presented these lines, but when viewed at a less dis-
tance no ray was visible except the brilliant one of sodium.
Janssen stationed himself on the side of the lake opposite the
fire, so that the light from the blazing pile, which was on a level
with the surface of the water, might penetrate strata of air satu-
rated with moisture.

It was necessary to ascertain if these effects were caused by
the water in solution in the atmosphere, or whether, as Mr.
Secchi thought, they were to be attributed to the vesicles of
which mist and fogs are composed. A direct experiment con-
firmed him in the opinion that they were produced oy the vapor.
Janssen operated with a tube thirty-seven meters in length,
which was filled with vapor by a steam engine of six horse-
power. Care was taken to prevent the tube from cooling, and
the light was furnished by a fiame of gas placed in the axis of
the tuoe. When the light passes through the tube filled with
vapor subjected to the pressure of seven atmospheres it shows
the principal telluric rays, among which Janssen places the



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Influence of Sodium upon Flame, 91

groups A and C and a large part of B, contrarj to Kirohhofi^
who attributes A and B to potassium. The red and yellow of
the spectrum of witter- vapor are more brilliant than the blue
and violet Therefore the color of the vapor of water should
be orange ; hence, also, the red of the setting sun, that is, of the
sun seen near the horizon. Janssen does not agree upon this
point with the conclusions of Prof. Cooke, which were pub-
lished in this Journal for March, 1866. According to the latter
the vapor of water absorbs most completely the jellow and the
red rays, hence the blue rays predominate in the spectrum that
is transmitted. Prof. Cooke has, however, discovered and de-
monstrated by his own researches (this Journal, [2], xli, 184,
also Journal de^ Pharmacie et de Chemie, June, 1866, p. 480),
the influence of the vapor of water upon the phenomenon in
question.

A new property of magnesium, — One evening while preparing
some perchlorid of manganese, MnCl' (this Journal, [2], xli,
107), with the peroxyd of manganese, the chlorhydric acid of
commerce and ether, I observed that the color was not green, as
it appeared to be in the daytime, but hhck, I was using ffas for
a lignt, and substituted in place of it first an oil lamp and after-
ward a wax candle, but the effect was the same, the color still
appeared only black.

The green color reappeared by the flame of magnesium, which
comports itself in this respect like the light of the sun. It is well
known that bright-tinted flowers, colored stuflb, or pictures, ex-
hibit much less brilliancy of coloring bv wax or even gas light
than when seen by the light of day, and should an artist, at the
close of the day, wishing to supply the waning light, continue
his work by the aid of wax lights or gas, he would be surprised
the next morning at the assemblage of colors he had maae the
evening previous. They would in no way represent his thought,
so difierent would they appear when viewed in the two lights.

By burning a thread oi magnesium a light may be obtained
which will make these colors appear the same as when seen \>j
sunlight itself. Colors do not mingle or interchange by this
light as they do by ordinary lights. Green does not appear to
be blue in it, neither does blue have the slightest appearance of
green. In short, all shades preserve the same appearance as
when viewed in the full light of day. The flame of magnesium
is whiter than solar light, and the blue predominates in it.
Chemistrv aids the painter not merely by furnishing colors
more or less bright, but it now gives him a new mode of illu*
mination by means of which he can labor at niffht without fear
of optical deception, as well as if it were daylight

The influence of sodium upon flame. — On inquiring the reason
for the extinction of color by the usual flame, which we have.



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D3 CorrespoTuknce of J. Nicklis,

just been dificaBsing, it will be found that numerous causes pro*
duce this e£fect, one of which is sodium, which burns with a yeU
hw (monochromatic) flame, that may be obtained either by bring"
ing common salt supported on platinum wire into the name of
the Bunsen lamp, or by burning alcohol saturated, with salt.
All the colors are altered by this flame, with the exception of
blue-violet, which is complementary to the yellow. Bed appears
black or white, sometimes bluish when it contains blue (see
below, physiological effects). Mixed green appears yellowish or
bluish (chlorophyl Schweinfurth green). The pure greens ap-
pear black (ex, MnCl*, MnBr*, Mnl« combined with ether,
baOMnO», Cr'O', gold leaf seen by transmitted light, Cr>Cl*,
Ac). Vide Annales de Chem. et de Phys., [4], •viii, 298, for the
* enumeration of the various colors which have been experimented
with.

The following table gives the result of some trials which I
have made with a spectrum prepared by applying pigments to
white paper. We give the composition of the spectrum and the
colors with which it was obtained.

Color* iMB by Colors seen by a

dajiif he Coloriog material. moaochromaMc ilama.

Bed. Ochre (Fe?03), - - - Black.

Orange. lodid of mercury (Hgl), ) -mx^'i.

Yellow. Chromate of lead (PbOCrO*). ] ^^"^^^

GreoD. Manganate of baryta, ) ni %

Blue. Aniline blue, f ' ' •^'*^*-

la this spectrum so wonderfully changed by the flame of alcohol
saturated with salt^ sunlight and the flame from magnesium in-
stantly restored the normal colors, even while the sodium flame
was burning in the neighborhood. They also reappeared by
gaslight, but with much less intensity, and when the colors are
not very brilliant they are modified as if they were illuminated
by the soda flame.

Thus etherial solution of perchlorid of manganese when im-
pure appears by gas light blaeh instead of green, A mixed green
composed of chromate of lead (PbOCrO') and ultramarine be-
haves in the same manner.

If the illuminating flame were saturated with sodium its ex-
tinctive effects would be still more energetic, ordinary flames
containing but very little of this metal. Spectral analysis shows
us that instead of completely extinguishing colors it merely al-
ters them a degree more or less, darkening some and enlivening
others, and creating confusion between blue and green.

The small quantities of sodium which all ordinary flames con*
tain, are derived from several sources., viz., the niineral matters
of wicks of lamps and candles, ashes of fuel and atmospheric
jair, which last, according to Bunsen^ always contains traces of it.



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Phynological effects of the Monochromatic Flame, 9^

Togel has determined the proportion of soda which illuminating
ffas contains (Joum. de Pharm. et de Cbem., October, 1866), and
Mulder has shown (in the same Journal, May, 1866), with what
facility marine salt volatilizes when heated with coal.

Small as the quantity of sodium is which illuminating gas
contains, it is sufficient to affect certain colors, and to produce
on a small scale all the effects of absorption or extinction which
are readily seen in a flame saturated with it. Examples of this
may be seen in certain green polors mentioned above.

Physialogioal effects of the monochromatic flame. — ^The foreffoing
results eicplain a well known phenomenon, which has hitherto
never been accounted for. In the flame of alcohol and salt, the
hands and face appear of a livid green hue, while the lips change
to a hlu^vioUi, This livid tint is known to all who have seen
punch or a pudding burn, and is due to the alcohol more or less
saline which is employed in these mixtures. Workmen at fur-
naces and forges are familiar with these peculiar tints, which
appear upon the features illuminated by their fires.

In the first case the effect is produced by the NaCl which the
alcohol contains of itself or which it derives from the alimentary
substances; in the latter case the soda is obtained from the dross,
and ashes of the combustible matters. The question arises, why
under these conditions, the natural flesh color is changed to a
bluish or livid green. The reply is evident It has been shown
above, that the colors which oeist resist the extinctive effects of
the soda flame are those which come from blue.

That there is blue in human blood may easiljr be seen by the
color in daylight of the large veins on the skin of the hand.
All the other tints which enter into the composition of flesh
color being extinguished except the blue, that shade alone re-
mains upon the face of the experimenter, but being also illu-
mined by a yellow flame, it is plain that the effects of the two
colors will be to produce a grem^ varying in shade from yellow-
ish to bluish according to the intensity of the blue, and produ-
cing a most sinister aspect on the human countenance. Tne eye
speedily accommodates itself to these effects, but I have good
reason for thinking that one cannot with safety, continue to work
for any great length of time by this monotonous light. The
retina ai^r a time becomes so much affected as not to be able to
bear without irritation either daylight or the ordinary illumina-
tion used at night, a result possibly caused by the absence of
chemical rays in the flame, or because it injures the optic nerve
which is poorly adapted to such a medium.

After sitting for a considerable time in the soda light, there
comes a time when it is difficult to distinguish between tne differ-
ent shades of the same color. I have many times seen a tuft of
leaves appear of the identical shade of the hand which held it, so



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M Correspondence of J. NickRs,

that the whole had the effect of a bronze, while at the beginniDg
of the experiment before the eye had become fatigued, it was easy
to distinguish between the violet of the chloroph jl and the livid
green of the flesh color.

Mnpbyment of the Sodium flame by artisU. — We have previ-
ously shown that the different colors of the spectrum may be
reduced to white or black, unless they contain blue which is the
only color unaffected by the soda flame.

In observing such a spectral im^ge it will be noticed, that if
all the colors are reduced to either white or black, the borders
are more or less darkened or dulled as in a photograph of the
spectrum. Looking at a painting, especially a pastel containing
very little if any blue, under these conditions, one is struck with
the fact, that although the colors vanish, the grayish tone which
represents them gives the appearance of a pencil drawing. Th^
model or plan exists by reason of the half tints so that by the
monochromatic light, one is sometimes able to go back to the de-
sign without touching the picture and can thus give in some sort
the autopsis of a work of art.

The name of sodium may yet aid the painter in comparing
shades, in grouping colors and weighing their tones.

In the same manner, two colors, for example two greens which
appear identical upon the palette, in the daytime, may be differ-
ent when seen by common evening light, and are more likely to
differ when viewed by the sodium flame, one being decolorized
and the other transformed into black. In the same manner, of
two redt seen under the same conditions, one may appear white,
while the other containing blue, will assume a violei'tint comple-
mentary to the yellow of the monochromatic flame.

Common salt ignited on a platinum wire in the flame of a
Bunsen burner, strikingly exhioits the chemical differences which
sometimes exist between two similar shades of color. This
means may be useful in distinguishing original pictures from
copies, for it is not likely that Raphael or Van Dyck, for instance,
exployed exactly the same pigments as their copyists have used.

if one desire to render the flame of a ^as burner or of an oil
lamp monochromatic, it cannot be done with NaGl, for the flame
is not hot enough to volatilize that compound. Metallic sodium
should be used for this purpose, which may be introduced into
the gas burner or held in the flame upon platinum wire.

PercUorid of Lead, PbCl^, — In connection with what we said
last year (this Journal, [2], xli, 107 and 55) upon the halogen
compounds corresponding to the peroxyds, we have since ob-
tained the compound PbCP corresponding to the peroxyd of
lead PbO*. Unstable in a free state, it may be preserved for
a long time in presence of a solution of chlorid of calcium.

It is preparea by passing a current of chlorine into chlorid of



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Perchlarid of LeaJL 95

lead held in suspension in a solution of CaCl of 40^ Beaum^.
The liquid becomes yelloir and acquires very curious properties.
Thrown into a small quantity of water, it gives a precipitate of
PbCl — with excess of water a brown precipitate is formed of
PbO^ PbCl« +2H0+ Aq=PbO« +2C1H+ Aq.

In this case the hydrochloric acid does not react, because of
the excess of water present, if there were less the result would
be PbO» +2C1H=2H0+Pb01+Cl.

The perchlorid of lead does not act upon the nitrate of bismuth,
behaving in this respect differently from TIGP (this Journal, [2],
xli, 107). When heated it blackens cane sugar but not glucose,
and hence may serve to distinguish between these two kinds of
sugar.

Treated with anhydrous ether and syrupy phosphoric acid, the
solution of perchlorid of lead thickens, ana yellow oily drops
appear, which are perchloro-plumbic ether. This ether readily
dissolves gold, and as the metal is taken up chlorid of lead sep-
arates assuming the form of the gold employed. The perchloro-
plombic ether readily decomposes ; the proaucts are protochlorid
of lead and chlorinated ethers. The ease with which chlorine
separates from it, is the cause of its solvent power on gold, in
which respect it is like the bodies presently to be noticed.

New solvents for Gold. — The perchlorids dissolve gold readily
when that metal is in the form of leaf, on account of the facility
of their decomposition with liberation of chlorine. If ethereal
solution of perchlorid of manganese be employed, the green color
of the manganese compound grows lighter in proportion as the .
gold dissolves, for MnCl» is reduced to MnCl, and the reac-
tion is complete, when the liquid has exchanged its green color
for the yellow of the solution of gold, (it is the same with MnBr*
and Mnl').* On evaporating the liquid, a film of gold adheres
to the vessel. The same solution added to FeOSO' yields the
precipitate of gold so characteristic for its dichroism.

The sesquichlorids, and the sesquibromids which are easily re-
duced — ^for example, the compounds corresponding to Mn'O*,
Ni*0', Co*0* ; also Fe*Br' even in presence of a certain pro-
portion of FeBr— dissolve gold ; Fe*I* is also a good solvent for
gold especially in presence of ether. It is only necessary to add
a small quantity of Fe*0* to the ethereal solution of iodhydric
acid, in order to dissolve the metal. This proves that iodine in
the nascent state acts upon gold. For this reason gold is acted
upon even by iodhydric acid in presence of ether. No action
takes place when only water is present. It can no longer be
said with truth, that free iodine does not act upon gold. I have
found that gold may be dissolved by it in presence of water,

♦ This Journal, [2], xli, 107.

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96 Correspondence of J. NickRs.

-when put into a close vessel and raised to a temperature of 60^.
The action is more slow if etlier is used in place of water. Ex-
posure to strong sunlight will hasten the solution.

Some new facts concerning amalgamaiion. — In vol. xli, p. 225
of this Journal, Prof. Silliman has described some properties of
the magnetic amalgam, composed of mercury and sodium. The
following experiment readily shows the great difference between
the action of mercurv and that of sodium amalgam.

Take a square of glass, to which apply side by side two
leaves of beaten gold. If a drop of ordinary mercury be placed
on one of these leaves, it adheres without sensibly increasing in
area. On the contrary a small drop of the amalgam spreads out
with great rapidity, so that in a few seconds the mercury has
covered a space many hundred times larger than that which the
original drop occupied.

I showed in 1853 (in this Journal)* that the metals moistened
by mercury are permeable to it ; that proposition has been veri-
fied upon the metals since discovered or prepared, viz., thaUium,
aluminium and magnesium. Thallium is easily amalgamated,
and becomes brittle by the penetration of mercurj ; on the con-
trary, magnesium and aluminium resist it^ action or are not
wetted by it until recourse is had to electric action, such as is
realized by the intervention of sodium or zinc.

It would be interesting to observe the deportment of indium
toward mercury. If it were capable of being moistened it would
form with it a brittle amalgam ; on the other hand, if it were not
moistened it would retain all its elasticity. I leave the question
to those who are fortunate enough to possess this metal so rare,
and so difficult to obtain in a metallic mass.f

Chemical synthesis, — M. Berthelot continues his beautiful re-
searches in synthesis, and is at present occupied with the gene-
ration of hydrocarbons. Our readers know that he formerly
obtained acetylene, C*H', by the direct union of hydrogen and
carbon (this Journal, 1862). Berthelot has lately shown that a
whole series of hydrocarbons, polymeric with C*H', may be
derived from it as follows :

Acetylene, C* H^

Di-aoetylene, - - - C« H* =2C*H2

Tri-acetylene or benzine, - Ci2H« zi:3C*H2

Tetracetylene or styrolene, - C^eH® =4C*H^



Retene, ... - C36ni«=9C*H2

This table is the result of actual experiment and not of theoret-
ical speculation.

• J. Nickl^a, On the Permeability of Metela to Meroiiry, [2], xv, lOT.
f A sheet of platinam that has been for four moDtha in contact with amalgam
of sodium still preseryes all its elasticity.



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Acclimation in Australia. — Spont^meoui Generation. 97

Berthelot has observed still another series of hydrocarbons,
between styrolene and retene, the boiling point of which is be-
tween 250 and 840^, and which possess to a great extent the
characteristic flaorescence of pyrogenic oils of resin. Berthelot
regards these hydrocarbons as C^H' six, seven, and eight times
condensed. Between 210^ and 250° there passes over a liquid
which, when placed in a freezing mixture, yields crystals of
naphthaline. The origin of this interesting hydrocarbon is
easily explained, naphthaline being in fact only pentacetylene
lessH*.

Pentacetylene. Naphthaline.

Naphthaline is produced equally well when acetylene is passed
into a tube heated to redness. There is, however, in this case
but a small quantity formed, for the acetylene is chiefly decom-
posed into carbon and hydrogen.

Acclimation of the Camel in Australia, — The introduction of
the camel into Australia has been previously announced, and it
was eflEected by the *' Soci^t^ d'Acclimatation." We now learn
that these animals have adapted themselves to that country, as
has been shown by a recent expedition consisting of seventy
horses, fourteen camels, and fifteen men. The springs of living
water upon which they depended having been dried up, sickness
broke out in the camp. The men fell back upon their stores of
spirituous liquors, the horses took to flight, while the camels
alone remained at their post. It is owing to this circumstance
solely that the expedition was reorganized. At last accounts the
caravan had arrived at Thompson river.

Acclimation of the Salmon. — ^The eggs of the salmon which
have been introduced into the waters of Australia have hatched
and the young fish are prospering. Ice has been used in the
transportation of the eggs, which, according to Mr. Youle, re-
tards the phenomena of embryonic evolution. This gentle-
man has found that the vitality of the eggs may thus be pre-
served for three or four months. It is in this manner that eggs
taken from the Bhine at HuDingen in Alsace have been success-
fully transported to Australia. Sweden and Norway are both
occupied in stocking their rivers with salmon, so that the fine
example of the Zoological Society of Acclimation will not be
lost

Spontitneous generation. — ^This interesting question is from time
to time discussed bv the Academy of Sciences, but without much
progress being maae toward a decision. Mr. Donn^, a naturalist
who formerly opposed the doctrine of spontaneous generation,
has made some late researches which have caused him to chanse
his mind on the question, and he has just ranged himself on the

Ax. JouB. Sol— Sbookd Sunt, Vol. XLm, No. 127.— Jait., 1867.
13



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06 Corre^imdence of J. NichUs.

side of Messrs. Jol j, Musset, and others, giving it as his opinion
that spontaneous generation is a possible &ct.

His later experiments, like those which he published an ac*
count of in 1863, were made with eggs. At that time he wrote :
'< The matter of which the egg is composed ought to be emi-
nently suited to a primitive organization. I will leave the en-
tire eggs to themselves, and when the alteration of their contents
has well progressed, I will examine with the microscope the in-
terior substance. If spontaneous generation is possible I ought
to find organissed beings there." The result was negative. Mr.
Bonn^ found neither mold nor infusoria^, and he decided against
spontaneous generation. Since then objections have been raised



Online LibraryJohn AlmonThe American journal of science and arts → online text (page 11 of 102)