Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1881-04-27
From Our Regular CorTespondentl
Washington Letter.

WASHINGTON. d. c., April ~, 1881.
During the past week the national acad'
envy of sciences has held one of its semi
annual sessions in Washington, and Its
principal event has been lecture by the
distinguished discoverer Prof. Bell, the
inventor Of the speaking telephone and
photophone. He recited the wonderful
facts discovered by him while engaged in
experiments for the improvement of the
photophone and that vast number oil sub
stances. solid, liquid and gaseous, possess
the property of emitting sounds upon the
falling thereon of intermittent rays OF sun
light, and that his experiments, TO measure
the emitted sound, mas resulted in the in
vention of an instrument styled by him
the spectrophone, that the scientists say
will prove of inestimable value in the field
of molecular physics.
The academcsns went wild over the
paper. At its conclusion, Prof. Rogers, in
the chair, said that, in consideration of the
vastness of the discoveries and their enor'
nous amplitudes, he could not refrain
from an expression OF his great joy, MS a
scientist, thereupon. He little anticipated
such glorious results. In view of this
magnificent contribution to the academy
by its honored guest. Prof. Bell, he sug'
eesled that vote of thanks be returned tC
the great inventor. and it was so ordered
by unanimous vote.
Prof Bell read his paper, reciting the
great facts recently discovered by him
with the cooperation of his associate, Prof
Tainter. He illustrated his remarks with
diagrams. The following abstract of hi:
paper gives the essential facts;
He had previously ascertained that theii
disks, of very many different substances
emitted sounds when exposed to a rapidly
interrupted beam of sunlight. He then
ascertained that sonorousness was, under
influence of Intermittent light, property
common to all matter. The satisfactory
results were communicated to the French
academy. During his absence in Europe
Mr.. fainter, at his suggestion, examined,
in the Washington laboratory, the sonor
Gus properties of vast number of sub
stances, and discovered that cotton wool
worsted, silk, and fibrous materials gen
orally, produced much larger sounds thei
rigid bodies like crystals He next founC
that the darkest shades produced the hes
effect-black worsted especially. Thel
he tried lamp black. A teaspoonful o
lamp. black was placed in test tube an'
exposed to an intermittent beam of sun
light, and the sound produced was mucl
louder then any produced before. Th
extremely loud sounds produced from
lam p. black demonstrated the feasibility o
using this substance in an articulatinI
photophone instead of the electrical re
ceiver formerly employed. In regard t.
the sensitive materials, in the case of sol
ids, the physical condition and the colo
are two conditions that remarkably intlu
ence the intensity of the sonorous effects
The loudest sounds are produced from sui
stances in a loose, porous, spongy cond
} ton, and from those that have the darkes
or most absorbent colors. He had not Il
yet found one solid body that failed to bt
come sonorous under proper conditions C
experiment
The deduction from these experiment
is that sonorousness is, under the diret
| action of intermittent sunlight, univers;
: property of matter.
| Prof. Bell made the gratifying statemen
! that his experimental examinations lwel
} still in their infancy, and that there wa
! no telling what great results might be de
veIoped IN the future.