322 Scientific Intelligence. 
A is the mechanical agape of heat, 
P the change of tensi 
a the coefficient on ss 
C the specific hea 
W the weight of thie length. 
Joule was the first to test the formula and his results did not 
entirely confirm the ers eso result. Edlund found that the 
formula led to a value of A=682°7 kilogrammeters, and concludes 
that the ct deca must be ccplatiel by the presence of inter- 
nal work in the wire. Riihlman is opposed to the conclusion of 
Edlund, and does ak think it probable that the specific heats of 
stretched wires can differ essentially from those of unstretched 
wires. H. Haga has accordingly tested the formula ee 
ally, measuring carefully the specific heats of the wires. From 
steel wire and a German silver wire the values of A were 437° 8 
and 428-1 respectively, and the author therefore concludes that the 
formula is correct and the mechanical theory of heat explains the 
changes of temperature which follow the extension and contrac- 
tion of wires.— Ann. der Physik und Chemie, No. 1, 1882, DP. ~~ 
hosphorescence. aone Apyery, R.E., at a meeting | of ithe 
oe © 
Balmain’s lumi paint, which is violet when excited by a: 
light, becomes more violet when it receives the blue ae of the 
solar spect The red end of the spectrum, however, extin- 
m. re 
guished the violet phosphorescence. The light of ce electric 
oe assed through a sheet of red glass also extinguished’ the 
phosphorescence. Ag oe eee believes that there are a series of 
octaves in the end of the spectrum which do not extin- 
guish the violet i ah The mean wave length of the rays excit- 
roe the phosphorescence was found to be 4300,—Nature, a 9, 
temperatures U and U’ of their boundaries. W. ye vn 
cusses these objections and thinks that the objections 1 and 3 
not pra hear ne and that the points can be embraced by the petitions 
He shows, in the case of 2, that Fourier’s theory demands that if 
the dondusd oli 4 is diminished by extension that the flow of heat 
between like particles is increased ayaa certain limitations).— 
Ann. der Physik und Chemie, No. 1, 1882, pp. 19-38. 5%. 
vf alegre observations with monochromatic light. — M. 
ZeNGER finds that benzine and benzylene in a compound prism 
together with quartz at an an le of 75° eliminate the extreme 
red, while pure anethol at the refracting angle of 75° ebnioates 
