382 Correspondence of J. Nicklés. 
On the Phenomenon called “ Spirit-rappings.”—The time 
not occupied by the discussion of the titles of candidates, has 
been filled; with communications, some of them of interest. The 
question also of “ table-turnings,” and “spirit-rappers,” has en- 
gaged the attention of a physiologist of Francfort, Dr. Schiff, 
who has given in a full session, a demonstration showing that the 
noise of the “‘spirit-rappers” ‘is not the result of a stroke of any 
part of the body on an external object; but that it is produced 
by means of the great peroneus muscle, the tendon of which 
passes behind the external malleolus, to which it is usually re- 
tained by a ligament. When this ligament fails, or when it is. 
much relaxed, if the muscle is suddenly shortened, the tension of 
the tendon becomes so great that it slips suddenly from the mal- 
leolus, producing a noise similar to that of a stretched cord sud- 
denly loosened.* M. Schiff by practice has become able to make 
r 
Restored from their surprise, the Academy hastened to change 
the subject, as if ashamed to occupy itself with the scientific ex- 
planation of a fact which for some time has occupied the popular 
imagination. : 
Evectricitryr—Electro-chemical action.—Works on Electricity 
_ electrodes become covered with gas, and take polarity ; and con- 
sequently they give origin to contrary currents which necessarily 
diminish the effect of the pile. To avoid such disturbing cau 
ses, M. Becquerel has contrived two pieces of apparatus for con- 
stantly depolarizing the electrodes, making them at every moment 
to change their polarity. The author has exhibited his apparatus 
in action before the Academy, and has since i lied it to the 
study of the principle which governs the disengagement of elec- 
tricity in chemical action, a principle which he first brought out 
in 1823, and which since has been adopted in the science. — 
: eobr. Austin Flint of Buffalo, at the commencement of the “ spiritsappet delu: ed 
a exposed the source of this noise in the same way precisely as Dr. HCD" 
Ds. = bie (mee eee rs che 
a 
