PROCEEDINGS. 
417 
Mr. E. W. Clarke then spoke on The Dalton centenary at 
Manchester and the Chemical Congress at Berlin. The first was 
in commemoration of the announcement of the atomic theory, 
October 21, 1803; it was attended by nearly all the leading chem¬ 
ists of Great Britain. The speaker delivered the principal address, 
pointing out the significance of the discovery. After the cen¬ 
tenary the speaker had visited the Berlin Congress and many of 
the best laboratories in Europe. He exhibited a Crooke’s spin¬ 
thariscope. [Hot published.] 
Mr. Gore spoke briefly of his attending a meeting of the Ber¬ 
lin Academy of Sciences when memorial addresses were made on 
Virchow, and of the coincidence that he was also present when 
DuBois Raymond introduced the newly elected Virchow to the 
Academy. 
573d Meeting. November 7, 1903. 
President Gore in the chair. 
Thirty-five persons present. 
Mr. A. L. Day spoke on The black body and the measurement 
of extreme temperatures. He outlined the history of the theo¬ 
retical study of the problem and showed how an artificial black 
body had been constructed. By the aid of this the relation be¬ 
tween the temperature and the total radiation, and also the wave 
length of radiation of maximum intensity had been expressed in 
the form of an equation; from this, temperatures outside the 
range of measurement could be calculated by extrapolation. 
[Published in Astrophysical Journal, vol. xix, p. 1 (1904).] 
The paper was discussed by Messrs. Bigelow, Abbot, and 
Waidner. 
Mr. C. E. Van Orstrand then presented some notes on The 
emission function, discussing mathematically the equation re¬ 
sulting from the work described by the previous speaker. [Pub¬ 
lished in Astrophysical Journal, vol. xix, p. 1 (1904).] 
