The pilot and transcript. [volume] (Baltimore, Md.) 1840-1841, 1840-12-28
MEDICAL COLLEGE OF ONO, l
Dec. 1e. $40.

,
Der Sir-Since my last communication the
weather has been mostly such as would not per-
init electrical experiments to be conducted /
have, however, determined several interesting
points. have not been able to procure eiectri-
cal excitement by letting off condensed ali in
Jet from an insulated metallic receiver. The
electricity procured in my last experiments, by
discharging high steam from an insulated boiler,
was not, as / suggested, produced by the me-
chanical friction of the elastic vapolr passing
through the contracted aperture.
The more prominent experiments have been
as follows:
l. Air condensed to two or three atmospheres,
and discharged by small aperture from an iRsu-
lated copper receiver, gave not the slightest cleo
trical excitement.
2. The steam OF water, raised to three atmos-
pheres, and discharged in a jet t7hiIe the boiler
tcaS enceloped IN a large flame Of alcohol gave
no electricity.
3. The same boiler, with steam raised to three
atmospheres, and the fire entirely extinguished,
gave electricity sufficient to cause the gold leaf
electrometer to diverge 10 its full extent, while
the steam was escaping from the Jet.
4. Steam raised to one atmosphere above SIM
pie boiling, in Marcet's boiler, and Kept up TO a
uniform pressure and temperate by moderate
alcohol fame the jet being op, and steam es
Gaping just as fast as generated, constant cur
rent OF electricity was supplied, the gold leaves
alternately expanding and contracting in regular
pulsations, delivering at each variation spark
to the contiguous tin foil.
s. The same as the above, except that the
heat and pressure were allowed to increase
there being more steam generated than was pei
mit,ed to escape. The electricity was as IN No
A, only somewhat increased.
6. The same as in and 5, except that the heat
and xvara aIUad IN decline the steam
escaping faster than it was generated. The cur
rent of electricity the same as in and ., but
somewhat less.
7. Alcohol of the specific gravity of $40 was
put into the boiler, instead of water, and the
steam raised to one atmosphere. On opening
the Jet and allowing the vapour TO escape, more
electricity was excited than with the steam Of
water.
8. The steam Of alcohol gave even more elec-
tricity when the fire was cxtinguisheo, before the
opening OF the jet, the leaves OF the elecirometeI
pulsating about twice per second.
8. The same as in s, except the use OF pitn-
balls, instead of the gold leaf electromoter. The
electricity was sufficient to move them.
10. The vapour of spirits of turpentine gave
electricity, so long as the more volatile part;
were escaping at temperature below 3UU de-
grees; but from 800 to $50 degrees, no electricity
appeared.
Conclusion. appears that electricity ac'
companies the escape of high steam whethei
the fire be under the boiler or not, whether the
temperature be decreasing, stationary, or IN
creasing. Whether it be produced by the va
Dor of other substances than water, IS not abso
iutelv determined by The above experiments
fer the alcohol though strong, was not absolute
" pure, and the oil of turpentine while It gay'
electricity might have been giving out som'
water which had commingled itself with tina
LIQUID Yet as the alcohol gave more electn
city than the water, it is probable that the eff
feet was not due alone TO the water which th'
alcohol contained. The absolute source Of tn
electricity is still some what questionable
Whether it be the effect of heat passing through
different substances in contact, the effect Q
chylnical action between the liquid and tn
boiler. or be absolutely the effect Of evapora
ton. due TO the formation of steam, require
I Still further research. The experiment Shout
/ be made with distilled water in a clean boile
of olatinum, where there would be no chyml
calaetion. mmy experiments, the electricity
seemed % accompany the evaporation, 70 b