48 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
velocity is dependent on atmospheric temperature and independent 
of barometric pressure. 
Mr. Durron thought that the extreme delicacy of this observa- 
tion would involve an uncertainty greater than the one which now 
inheres in the determination. 
239TH MEETING. OcTOBER 27, 1883. 
The President in the Chair. 
Forty-seven members and guests present. 
The Chair announced the death of two members since the last 
meeting—LrEonARD Dunnett GALE and Exisua Foore. : 
Announcement was also made of the election to membership of 
Cuar.es DootirrLe WALCOTT. 
Mr. T. N. Griu made a communication on 
ICHTHYOLOGICAL RESULTS OF THE VOYAGE OF THE ALBATROSS. 
Mr. ALEXANDER GRAHAM BELL made the following communi- 
cation on 
FALLACIES CONCERNING THE DEAF, AND THE INFLUENCE OF SUCH 
FALLACIES IN PREVENTING THE AMELIORATION 
OF THEIR CONDITION. 
It is difficult to form an adequate conception of the prevalence 
of deafness in the community. There is hardly a man in the 
couniry who has not in his circle of friends and acquaintances at 
least one deaf person with whom he finds it difficult to converse 
excepting by means of a hearing-tube or trumpet. Now is it not 
an extraordinary fact that these deaf friends are nearly all adults? 
Where are the little children who are similarly afflicted? Have 
any of us seen a child with a hearing-tube or trumpet? If not, 
why not? The fact is that very young children who are hard of 
hearing, or who cannot hear at all, do not naturally speak, and this 
fact has given origin to the term “ deaf-mute,” by which it is cus- 
tomary to designate a person who is deaf from childhood. 
“But are there no deaf children,” you may ask, “ excepting 
those whom we term deaf-mutes?”’ No; none. In the tenth census 
