V(M-. XXV. No. -2.] 
POPULAR SCIENCE ITEWS. 
29 
will rapidly diminish until the rings disappear in 
the autuiun. Uranus is still in the. constellation 
Virgo, rising somewhat before midnight. It is 
nearly stationary among the stars, moving first a 
little eastward, and then (after P'ebruary 4) mov- 
ing westward : but the whole motion Is only about 
half the diameter of the moou. Xeptune is in 
(juadrature w ith the sun on February 22. It is in 
the constellation Taurus, a little west and north 
of the group of the llyades. 
The Constellations. — The positions given are for 
,10 P. M. February 1, 9 P. M. February 15. and 8 
[p. M. February 28. (jemiui Is near the zenith, the 
fprincipal stars. Castor and Follux, lieiug a little 
south and east. Cauis Minor, with the first niag- 
|aitudc star Procyon, is on the meridian to the 
Buth ; and below that is Canis Major, with Sirius, 
Jtlie bright<"st of the tixed stars. Cancer is just 
ast of tiemini, and Lej is about half-way from 
[tlte easUu-u horizon to the zenith, while Virgo is 
just rising in the east. I'rsu Major is high up in 
|the northeast, and Bootes is below it on the hori- 
|Zon. L'rsa Minor aud l)raco lit' prineii)ally to the 
St aud Ijelo-.v the pole star. (Jassiopeia is in the 
orthwust, about the same altitude as the pole 
tar. .lus, w(^st of tlie zenith is Auriga; below 
this and a little to the north of west is Perseus; 
ud .Vn<lromi;da is near the horizon, below Per- 
eus. Taurus, witli tlie gronjis of I'leiades aud 
lyades, is a little south of west, and below it are 
Lries and Pisi;es. Orion is about half-way be- 
R'eeu 'I'aurus and the southern meridian, tlie 
ftrineipal stars being at a little lower altituile than 
hose of Taurus. M. 
I.AKV. FoKK.ST, li.i.., .Jan. 4, 1x91. 
sulphocyanate of allyl (C^ II5 N C S). It does not 
exist as such in the soeil, but is produced by the 
decomposition of the potassium myrouate by the 
action of water. This volatile oil is a very power- 
ful irritant, aud the characteristic properties of 
mustard plasters are due to its formation when 
the ground seeds are moistened. It has also been 
produced synthetically. 
I. C. \y., Neir York. — What is the cause of the 
corrosive effect ou cloth of the stains of iron rust, 
commonly known as iron niouldi' 
Ansirrr. — Iron rust, or ferric oxide, (Fe., O,). 
slow ly oxidizes cellulose, of which cotton or lineu 
cloth is priucipally composed, being at th(! same 
time reduced to ferrous oxide (Fe O). The fer- 
rous oxide takes up additional oxygen from the 
air, aud is ie-<„'onverted to the ferric oxide. The 
process is thus practically one of slow combustion, 
the iron acting as a carrier of oxygen to the cellu- 
lose. A similar corrosive effect is seen around the 
heads of rusty nails driven Into wood. 
fR'edieiRe aipd ^hfaPFaaQ^. 
(^UK.STIUN'S AND ANSVVKIiS. 
LKTTKK.S yf inquiry should enclose a two-cent 
amp, as well as the name and address of the 
^•riter, which will not be published. 
Qi;ESTif>.\s regarding the treatment of diseases 
iiiuot be answered in this uolamii. 
J. II. .1., Te/un. — What reaction ensues when the 
hyru^) of iodide of iron is mixed w ith an aiiueous 
ttlutioa of ohlorate of potash :■ Free iodine appears 
» be formed. 
-•iMsicf-r.— The r(factioii is undoubtedly one of 
nidation, the irou being changed to the ferric 
auditlou. The follow iug toniiula will illustrate 
he probable reaction : 2Fe I -|- K CI O,, = Fe.^ (),, -\- 
'Cl -|- I — 1. There are probalily other reactions 
the mixture, and you will doubtless find that 
kydriodic acid is formed to a small amount. 
IN(ji IHKK. Cleveland. — How is it possible for 
neteors to become heated by friction when pass- 
ng through the atmosphere^ A cannon ball does 
liiot have its temperature perceptibly laised by 
limilar means. 
Answer. — The speed with winch the bodies 
Tiuown as ineteors enter and pass through the 
atmosptiere is so much in excess of that of a can- 
non l>all that there is no comparison between the 
two bodies. A piece of iron may be heated by 
pounding it ou an anvil, and the atmosphere acts 
like an anvil to the extra-terrestrial bodies which 
enter it. It can l)e shown by a mathematical cal- 
culation that the speeil of the meteorite and the 
resistance of the atmosphere are sufficient to pro- 
<Iuce the degree of heat observed. Still, as you 
suggest, the heating is for a very brief time, "and 
the larger specimens show the efl'ects of fusion, or 
Incandescence, onlj' superficially. 
W. S. R., Illinois. — Is the iriitating property of 
mustard due to the oil of the seeds or to some 
other chemical substance? 
Anstoer. — Mustard seeds contain a substauce 
which is a true fixed oil, being a combination of 
glycerine with fatty acids, aiid is as bland and 
mild as any vegiitahle oil. It is extracted from 
the seeds by pressure, aiid from the residue w hich 
remains the volatile oil of mustard is obtained by 
diatillattou with water. ITiis is chemically an i»cj- 
LITEKAKV N'O'J'ES. 
Insecta. bv Alphens Hyatt and .1. M. Arms. 1>. C. 
Heath & Co., Boston. Price, .$1.00. 
This interesting little work is exactly what 
every student and lover of nature needs to guide 
him in his studies of the countless forms of com- 
mon animals comprised imder the general name of 
iusects. All the various species and varieties are 
fully described and beautifully illustrated, while a 
thousand interesting facts are given concerning 
their structure, life, and habits. No better book 
can be found for those <'liapters of the Agassiz 
Association devoted to the study of natural his- 
tory. 
Inorganic Chemislry : Theoretical aud J^raetical, by 
William dago, F. C. S. Longmans, (ireen & ( 'o!, 
New York. 
This work is published as a "maniuil for ad- 
vanced students," but it .seems equally well adap- 
ted for beginners in chemistry who intend to 
pursue their studies beyond the usual elementary 
course. The arrangement and treatment of the 
subject is most excellent, and includes the most 
recent adv.inces and discoveries in the science. 
Tlie work is worthy the attention and favorable 
consideration of both teachers and students of 
chemistry. 
Greek for BeyinHeri), (ijl.OO), by Kdward U. Coy, 
.M.A., is a recent publication of the .\merican 
Book Company, of New York, aud is equally val- 
uable with Us previous Issues of educallonal' text- 
books. 
Messrs. Funk it Wagnalls, of New York, are 
about to pulilish a new single-volume Standard 
Dictionary of the Ewjlish Language -whiiih willcora- 
I)rise many new and valuable features. Full in- 
formation regarding it can be obtained by address- 
ing the publishers. 
The Anurican Annual of Photography and Photo- 
graphic Times Almanac should be in the possession 
of every photographer, both professional and ama- 
teur. 'I'he large amount of useful information 
and numberless practical hints which it contains 
are agreeably supplemented by many beautifid 
ami .artistic photo-gravures froin the negatives of 
the most celebrated .artists. Published bj' the 
Scovill & Adams Company, New York. Price, 50 
cents. 
Lee & Shepard, of Boston, liave favored us with 
the All Around the Year Calendar, which is one of 
the daintiest and prettiest ever published. The 
calendar for each month is embellished with a 
vmlque and beautiful drawing, the whole forming 
a pleasant souvenir of the year 1891. 
Pamphlets, etc., received: TTie Climate of the 
Eastern Shore of Maryland, by C. W. ( bancellor, 
M. D. ; Ahnormal Intra-Thoracic Air Pressures and 
Their Treatment. l)y Charles Deuison, JI. D. ; Be- 
pnrt upon Coke Iron Manufactures for the City of 
Marquette, Mich. ; and the various Reports of the 
Uiiitcd StBtea i^bverument departments; 
THE COMPOSITION OF KOCH'S LYMPH. 
\Vk make the following selections from Dr. 
Koclfs original report as cabled to this country : 
Two months ago 1 published the results of my 
experiments with the new remedy for tubercu- 
losis, since w hicli time many physicians who re- 
ceivisd the preparation have been enabled to 
become acquainted with its properties through 
their own experiments. So far as I have been 
able to review the statements published and the 
commuications received by letter, my predictions 
have been fully aud completely confirmed. The 
general consensus of opinion is, that the remedy 
has a specific action upon tid)ercular tissues, and 
is, therefore. iii)plicable :is a very delicate and 
sure reagent for discovering latent, and diagnosing 
doubtful tuberculous processes. Regarding the 
curative cttects of the remedy, most reports agree 
that, despite the comparatively short duration of 
its ai)plication, many patients have shown more 
or less pronounced improvement. It has been 
affirmed tliat in not a few cases, even a cure has 
been established. Standing (juite by itself is the 
assertion that the remedy may not only be dan- 
gerous in cases which have advanced too far, — a 
fact which may forthwith be conceded,— but also 
that it actually promotes the tuberculous process, 
being iherefon.' injurious. 
During the past six W(-t'ks I inysidf have had 
opportunity to biing togetlicr further experience.s 
touching till' curative eft'ects and diagnostic appli- 
cation of the remedy in the cases of about out- 
himdred and fifty sufl"erers from tuberculosis td' 
the most varied types in this city and in thi« 
Moabit Hospital. I can only say that everything 
I have latterl ,• seen accords with my previous ob- 
servations. There lias been nothing to modify in 
what I before reported. As long as it was only a 
(piestion of proving the accuracy of my indio.t" 
tions. it was needless for anyone to know what the 
remedy contained or whence it was derived. On 
the contrary, subsequent testing would neoessa-- 
rily be more unbiassed the legs people knew of 
the remedy Itself. Now, after siifiicleut confirm- 
atory testing, tlie Inipoitance of the remedy is 
proved, my next task Is to extend my study of 
the remedy beyond the field where it has hitherto 
been applied, and. if possible, lo apjily the prin- 
ciple underlying the discovery to other diseases. 
This task naturally demands a full knowledge 
of the remedy. I therefore consider that the tune 
has arrived when the re(juisite Indications in this 
direction shall be madcs This is done in what 
follows. 
Before going into the remedy itself, I deem it 
necessary for the better understanding of its mode 
of operation to state briefiy the way by which I 
arrived at the discovery. If a healthy guinea-pig 
be inoculated with the pure cultivation of German 
Kultur of tubercle bacilli, the wound caused by 
the inoculation mostly closes over with a sticky 
matter, and appeai-s, in its early days, to heal. 
Only after ten to fourteen days a hard nodule pre- 
sents Itself, which, soon breaking, forms an ulcer- 
ating sore, which continues until the animal dies. 
Quite a different condition of things occur when a 
guinea-pig already suffering from tuberculosis Is 
inoculated. An animal successfully inoculated 
from four to six weeks before is best adapted for 
this purpose. In such an animal the small inden- 
tation assumes the same sticky covering at the 
beginning, but no nodule forms. On the contrary, 
on the day following, or the second day after the 
iuo«ulatloQ, the place where the lyuj^ UW-""^ 
