Year: 1869

sor Agassiz assured the audience that these
pests were not peculiar to the swine, but,
in some modified forms, we're found in all
meats, and especially in fish. He advised
that food should be well cooked.


On New Method Of Producing by the
Electric Spark Figures similar to those of
Lichtenberg, by Professor Blake, of the
Cornell University, Ithaca, N. Y. Figures
have been produced by allowing the cleo
trio spark to strike on the surface of pitch
or any other non-conductor, and then
sprinkling the surface with fine dust. The
electricity retained on the non-conducting
surface attracts the dust to itself, and q
figure is thus formed. When the electricity
employed was positive, the figure was o
star with many rays; when Negative, q
ring or wheel with more or less curved
spokes. These are the figures of Lichten-
berg, which, since their discovery in 1779,
have excited great deal of interest, and
have been the subjects of elaborate inves-
LEGATIONS.


In 1862, Professor Rood, of Columbia Col
lege, showed that figures similar in form
were produced by allowing the spark to fall
on sensitized film of collodion and devel
oping in the ordinary way like photo
graph. The object of Professor Blake's pa
per was to describe third method by which
similar figures are produced. If coating
of pitch be spread by heat over one side of
n piece of sheet tin, and on the pitch sur
face thus prepared, when entirely cold and
hard, an electric spark be allowed to fall,
no visible effect will be produced. On hold
ing the plate (metal side DOWN over lamp
for an instant, the pitch becomes soft
ened and beautiful figures suddenly appear
on its surface, as if impressed there by an
engraved seal. Specimens of these in great
variety were shown to the audience, and ex-
cited general admiration for their sharp
ness and beauty. The figures are, for pos
tive electricity a star with many rings
for negative electricity, q ring but the
lecturer explained that owing to the we'll
known oscellatory nature Of the discharge
the figures consisted generally, if not al
ways, of positive and negative figures su-
perposed, the general aspect of the figure
being determined by the kind of electricity
employed. 1t was further shown that if the
surface of the pitch be soft, by heat, ochen
the Sp0rh strikes, that the figure is at once
produced, and no development is re-
Quircd. Many notifications of the original
experiment were described and illustrated
by specimens of the figures produced. At
the close of the reading, Professor Henry,
of the Smithsonian Institution, compli-
mented the paper, and made some remarks
on his own early discovery of the oscilla-
tory nature of the discharge of the Leyden
jar. f" -


Professor B. Waterhouse Hawkins, of
New York, was introduced, and made some
remarks on visual education. Through the
organ Of vision, he said, we took in larger
number of impressions with the least posi-
bic amount of fatigue than by any other
means Of absorbing knowledge. The valu-
able qualities of the eyes were in close
association with the rights of women, and
his idea of the rights OF women was the in
creased power of their educational facul-
ties in reference to children who SO con-
stantly sat at their mothers knees and
asked questions almost invaluable about the
nature of that which they saw but could not
always understand. Such pertinent ques-
tions as, Mamma, what is that creature ?"
or Mamma, what is the good of this ;"
were too often evaded in consequence of the
inability of mothers to read rightly the
beautiful stories which nature presented.
The powers of observation, he thought,
should be more highly educated than
those Of the memory which we had found
in SO many instances failed in producing
the results expected. He advised the estab-
lishment of museums in connection with
large public parks, such as the museum in
the Central Park in New York, so that
healthy exercise and amusement might be
happily combined. While receiving i'm
pressions the powers of observation would
be educated. Such institutions, he thought,
would do more good than the reformatory
institutions now existing and he would
have every name represented therein freely
translated into simple and understandable
language. The present modern system OF
education was false, he said, when it with
drew boys at an early age from their mo-
theirs influence, under the pretence that
they must receive an education which it was
impossible for woman to give. He would
have all boys remain longer under the in
struction Of their parents. ... -.-


The remarks of Professor Hawkins
brought Professor Agassiz to his feet, who
spoke with great enthusiasm as follows :
"I am as convinced as q man can be that
the system Of public education is on the
eve of very extensive reform. The world
has been taught words dictated by autho-
rity thus far. The. world needs knowledge
and training in independent thought, and
it is only the study of nature which will
give us the last. But / am satisfied that
the basis of the future of education will be
the contemplation of the works of nature
no longer the study of the languages, NO
longer the study of the human mind, NO
longer the process of mathematical reason
ing, for though they must form part Of
liberal education, they should come after
the organs have been trained through OBJ
servation, and the mind taught to argue by
comparing these observations"