the tap is turned on again, in order to establish communication with the
exhausting tube. The tap is then closed, the mercury ascends again, and
this action keeps on repeating.

[Illustration]

* * * * *

NO ELECTRICITY FROM THE CONDENSATION OF VAPOR.--It has been maintained by
Palmieri and others that the condensation of vapor results in the
production of an electrical charge. Herr S. Kalischer has renewed his
investigations upon this point, and believes that he has proved that no
electricity results from such condensation. Atmospheric vapor was condensed
upon a vessel coated with tin foil, filled with ice, carefully insulated,
and connected with a very sensitive electrometer. No evidence could be
obtained of electricity.--_Ann. der Physik und Chemie_.

* * * * *




THE ELECTRO-MAGNETIC TELEPHONE TRANSMITTER.


An interesting contribution was made by M. Mercadier in a recent number of
the _Comptes Rendus de l'Academie Francaise_. On the ground of some novel
and some already accepted experimental evidence, M. Mercadier holds that
the mechanism by virtue of which the telephonic diaphragms execute their
movements is analogous to, if not identical with, that by which solid