On the Telephone. 77 
resistance simply renders the sound of the voice of the distant 
speaker fainter, as if he had gone further off, but in no way 
alters the quality of the sounds heard. Professor Bell has even 
spoken through a resistance of 60,000 ohms (the resistance of 
the Atlantic cable is equal to 7,000 ohms). 
Various practical applications of the telephone at once suggest 
themselves. It is already largely in use in the United States for 
commercial purposes. It has been successfully tried in diving 
and mining operations in this country. In physical research it 
promises to be the starting point of new investigations, and as a 
delicate phonoscope, or sound test, it will doubtless be most 
useful both in the lecture-room and physical laboratory. The 
telephone also reveals the existence of very feeble electric currents 
by the audible vibration of its iron disc. So prompt and sensitive 
is it to the slightest fluctuation in the strength of the current 
traversing its coil that it is not unlikely it may be of use in searching 
out rapid and feeble variations in a current that may escape 
detection by a galvanometer, owing to the inertia of even a light 
magnetic needle. Information as to the duration and character 
of rapidly intermittent currents is needed in medical science and 
not improbably the telephone may be able to furnish this infor- 
mation, when associated with a chronograph. 
The first attempt to transmit sounds by electricity is due to 
Philip Reis, teacher of natural history in a grammar school at 
Freidrichsdorf near Homburg. A brief reference to what Reis 
accomplished may here be of interest. I am indebted to Dr. 
Messel, a name well-known to chemists, who was a former pupil 
of Reis and eye-witness of his early experiments, for the following 
interesting letter on this subject :— 
“‘ Reis’ first experiments date as far back as about 1852. But at that 
time ended in failure, and were not resumed as far as I know till 1860. 
The first publication about Reis’ telephone appeared in a daily paper of 
Frankfort-on-Main, which however I have not succeeded in procuring. 
Reis gave his first public lecture on October 26th, 1861, when he showed 
his telephone before the Physikalische Verein (Physical Society) of 
Frankfort-on-Main, and I send you herewith a copy of his paper. 
‘‘'The original telephone was of a most primitive nature. The trans- 
mitting instrument was a bung of a beer barrel hollowed out, and a cone 
formed in this way was closed with the skin of a German sausage which 
did service as a membrane. To this was fixed with a drop of sealing 
