The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1883-04-07

Synopsis of the Lecture ON EAectrO-
MetaIurgy Delivered at Western Mary
land College, by Prof. w. III. thinner
man.
[Reported for the Democratic Advocate.
Of all the lectures delivered at Western
Maryland College on scientifcal subjects dur
ing the present year none were more inter
estipg. important and profitable than those
on electro metalurgy. After having made
few remarks to the class in regard to the great
amount of labor required in preparing suita-
BILE appliances, in order to show Dy expert
ments the utility and beauty of science, the
Professor spoke somewhat as follows with
reference to the rise and progress of the APP
plication of scientifcal principles to manu-
featuring purposes: There are two circum-
stances which almost invariably demand
especial notice First, that the discovery
has been the result of accident, being
revealed only through investigations I'M
dertaken for other purposes, rather than
through an attempt at discovery itself; and,
second, that when the discovery has been
clearly pointed out many objections are made
which reflect more or less upon the discov-
erer, as to its originality with him, since in
all probability many results previously OBJ
tanned may be relative to the subsequent re-
suit Such was the case with the beautiful
as well as the interesting and profitable art,
the fundamental principles of which will be
before you this afternoon. After
Galvani'S discovery in 1889, and the lnven-
ton of tho voltaic pile in 1900, Cruickshanks
of Woolwich constructed the first battery ever
made-known formerly as the trough battery
of Cruckshanks, and now as the galvanic
battery. Acetate of lead was decomposed by
this battery, and the appearance OF the metal
upon the negative end of the wire was eX-
planned by saying ''the metal has revived.
Brugnatelli, along with several others, had
made similar experiments and reached similar
results AIMEE, known to all galvanists on ac-
count of the battery bearing his name, says:
ELECTRO metalurgy may be said to have its
origin in the discovery of the courtant battery
by Prof Daniel; for in that instrument the
copper is continually reduced npon the mega
tive plate Another quotation was here
made from the same author, respecting the
formation of copper upon metal, after which
he said: Much weight must be attached to
Thomas Spencer's experiment, made with
modification of the Daniels battery; having
deposited copper coating upon penny and
having broken its connection with the zinc
plate, he (Spencer) removed the copper coat
ing from the penny and found it to be an eX-
act counterpart of the coin. Its useful apph-
cation was not suggested to him till sometime
varnish upon a slip of copper which he was
about to use in the same way as the penny
had been, and observing that no deposit &C.
Cured where the varnish adhered, he con-
ceived the idea of copying in relief by means
of the electric current, and carried the idea
into effect. Next came the discovery of en-
craving in relief by Galvani. Much discus
sion ensued; great minds were set at work;
papers were read before scientific bodies;
soon important improvements were annexed.
The use of plumbagO coating was the first
improvement introduced; its office was that
of affording n conducting surface to non-con-
Quoting bodies. This discovery is due to
Robert Murray, whom the Professor eulogized
to some extent. Electro metalurgy by this
discovery was freed from every bond. No
longer was metallic moulds necessary, or
moulds having metallic surfaces; forming this
surface was a tedious process, and only appll-
cable to certain substances. The separate
cells to which the current Is transferred by
wire from the generating cells was next in
troduced The following are the laws Of
deposition, and are the same in substance as
Spencer's:
Law 1.-The metals are invariably thrown
down as a black powder, when the current OF
electricity is so strong, in relation to the
strength of the solution, that hydrogen is
evolved from the negative plate OF the decom-
position cell.
Law EVERY metal is thrown down in a
crystalline state when there is no evolution of
gas from the negative plate Or no tendency
thereto.
Law 3.-Metals are reduced in the reguline
state when the quantity of electricity, in re-
lation to the strength of the solution, is INSULT
Client to cause the production of hydrogen in
the negative plate ofthe decomposition trough,
and vet the quantity of electricity very nearly
suffices to induce that phenomenon.
Many experiments were made at this point,
showing mainly the chemical effects of the
galvanic current and the chemical changes IN
the battery. Among the experiments were
the decomposition of water and the effect OF
acidulated water upon zinc. After which he
said; To begin with chemical effects we
must begin with the chemical changes in the
battery, for the changes which go on IN the
battery are but prototypes of those effected by
the current in the distant cells, the wires
serving as electric roads or ways, called cleo
trodes. The telegraph is an illustration of
this. Here was introduced concise descrip-
ton of the manner in which zinc placed in
calculated water decomposes and how the
chemical changes take place. Theories and
their objections were satisfactorily discussed,
and the enfeeblement of the current was given
a due consideration, the causes of which were
dealt with and clearly pointed out. Daniels !,
Sine's, Grove and the Bunsen bicarbonate
batteries were described and their pecullaritles
pointed out. The Bunsen and others were
used to make the explanation more forcible.
Experiments were made in silver and copper
plating A watch-case was plated with silver;
it will be on exhibition at Hyder' jewelry es-
adjustment. A brass rod was also subse-
uuently FURNISHED. Other experiments also
were made, The following laws of electro
lysis were announced;
Law 1.-Electrolysis cannot take place un-
less the electrolyte is conductor. Ice oxide
of lead, chlorate ofsilver, ETC., must be fused.
Law 1.-The energy of the electrolytic ac-
ton of the current is the same in all parts.
Law 3.-The same quantity of electricity
that is the same electric acknowledgements
chemically equivalent quantities of all bodies
which it traverses, from which it follows that
the weights of elements separated IN these
electrolytes are to each other as their chem
ical equivalents.
Law 4.-The quantity of a body decom-
posed in q given time Is proportional to the
strength of the current
Molecular motion was next illustrated by
means of the gyroscope, the motion being in
different directions according as the gyroscope
was over or underbalanced, and when it was
perfectly balanced no motion in any direction
ensued.
When suitable arrangements have been
made the public will be invited to attend these
important courses of lectures, though any one
is now welcome to attend them who may see
proper to come. The lectures begin promptly
at half-past two every Thursday afternoon
We are certain all who may come will be
pleased, instructed and entertained by the
forcibe style of these lectures. The Seniors,
we think, appreciate the Professors cndeav-
ors, for no one speaks of being disappointed,
but on the other hand always depart anxiously
awaiting the lecture in store for them.
Owings Mills Items.
On last Sunday the messenger of death
summoned from our midst Rev. w. F. Lock