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l§77-] Recent Advances in Telegraphy » 
and passing the complex current so produced through as 
many separate receivers of this kind, that each receiver will 
only respond to its own particular set of intermissions. 
For the sounding-pipe of each receiver can be so constructed 
as to resound only to the vibrations set up in the tongue by 
a particular series of intermissions. In this way several 
distinct notes maybe simultaneously telegraphed, each note 
being used for a separate message. 
The receiver shown in Fig. 16 has been called the “ phy- 
siological receiver,” since it depends for its aCtion on the 
contaCt of living animal tissue with a conducting surface. 
It is the most interesting of the two, because its aCtion has 
not hitherto been explained. If the intermittent current 
from the line is passed through the tissue to the conductor, 
