THE YOUNG SCIENTIST. 
71 
WELLS' COMET, 1882. 
Mr. S. C. Wells, Assistant at Dudley Observa- 
tory, at Albany, N. Y., discovered a comet of 
much prominence March 18. 
From The Science Observer, of Boston, a peri- 
odical devoted to original astronomical work, 
we glean the following information: During 
the latter part of May the comet will be seen 
low in the N.W., with the bright star Capella 
15^^ to the left. 
Director Boss says of the comet : " It is evi- 
dent that the comet should liave a brilliant 
career; its light at perihelion (June 1) should be 
more than three thousand times greater than 
at discovery. I believe that the comet has a 
large and active nucleus, and if this be true, we 
ought to see a tail of immense proportions in 
June." This comet was unusually bright at 
discovery, considering its distance from the 
Sun, and its elements are very different from 
known comets. 
Penn Yan, Yates Co., N. Y. 
Silvering Iron. 
A manufacturer in Vienna employs tlie follow- 
ing process for silvering iron : He first covers 
the iron with mercury, and silvers by the 
galvanic process. By heating to 300° C, the 
mercury evaporates and the silver layer is 
fixed. Ironware is first heated with diluted 
hydrochloric acid, and then dipped in a solution 
of nitrate of mercury, being at the same time in 
communication with the zinc pole of an electric 
battery, a piece of gas carbon or platinum being 
used as an anode for the other pole. The metal 
is soon covered with a layer of quicksilver, is 
then taken out and well washed and silvered in 
a silver solution. To save silver the ware can 
be first covered with a layer of tin ; one part of 
cream of tartar is dissolved in eight parts of 
boiling water, and one or more tin anodes are 
joined with the carbon pole of aBunsen element. 
The zinc pole communicates with a well cleaned 
piece of copper, and the battery is made to act 
till enough tin has deposited on the copper, 
when this is taken out and the ironware put in 
its place. The ware thus covered with tin 
chemically pure and silvered is much cheaper 
than any other silvered m.etals. 
Writing with. Lemon-juice. 
Father John Gerard, of the Society of Jesus^ 
who was confined and cruelly tortured in the 
Tower of London at the end of Queen Elizabeth's 
reign, was in the habit of writing letters in 
orange or lemon juice to his friends. The 
manner in which he thus baffled the vigilance 
of his jailers is described in detail in his highly 
interesting autobiography, published a few 
years ago by the Kev. Father John Morris. 
Father Gerard says : 
" Now lemon-juice has this property, that 
what is written in it can be read in water quite 
as well as by fire, and when the paper is dried 
the writing disappears again till it is steeped 
afresh, or again held to the fire. But anything 
written with orange-juice is at once washed out 
by water and cannot be read at all in that way ; 
and if held to the fire, though the characters 
are thus made to appear, they will not dis- 
appear ; so that a letter or this sort, once read, 
can never be delivered to any one as if it had 
not been read. The party will see at once that 
it has been read, and will certainly refuse and 
disown it if it should contain anything danger- 
ous." 
One result of Father Gerard's orange-juice 
correspondence was that, with the aid of zealous 
friends outside, he effected his escape from the 
Tower in 1597- The last ten years of his life 
were spent in the English College at Eome, 
where he closed a long, arduous, and meritori- 
ous career on July 27, 1630, aged seventy-three.— 
The Budget. 
To Clean Paint. 
When paint is washed with any strong alka- 
line solution, such as soda or strong soap, the 
oil of the paint is liable to be changed to soap 
and the paint is seriously injured. To avoid 
this take some of the best whiting, and have 
ready some clean warm water and a piece of 
flannel, which dip into the water and squeeze 
nearly dry; th^n take up as much whiting as 
will adhere to it, apply it to the painted sur- 
face, when a little rubbing will quickly remove 
any dirt or grease stains. After this wash the 
part well with clean water, rubbing it dry with 
a soft chamois. Paint thus cleaned will look as 
well as when first put on, and the operation 
may be tried without fear of injury to the most 
di^licate colors. It answers far better than the 
use of soap, and does not require more than one- 
half the time and labor. Another simple method 
is the following: Put a tablespoouful of aqua- 
ammonia in a quart of moderately hot water, 
dip in a flannel cloth and with this merely wipe 
over the surface of the woodwork. No rubbing 
is necessary. The flrst recipe is preferable, ex- 
cept where the paint is badly discolored. 
A Scientific Joke. 
A German newspaper some time ago related 
an amusing story of the famous scientist, Alex- 
andei' von Humboldt, who took advantage of 
the exemption from duty of the covering of 
