4 
Physics. 413 
tual angular measurement. The yellow sodium light is wanting. The 
chlorids of copper, platinum, gold, mercury, nickel, cobalt, zine, iron, 
sodium, potassium, and barium, all exhibit the characteristic violet light 
when sufficiently heated. The explanation of these phenomena is not 
apparent in the — aha of our knowledge —JL. and £, Phil. nee 
xxiv, 417, December, G. 
n the Solar Becabein m.—Merz has communicated a few notes on 
the Dsdicetithen of the spectrom and kindred subjects, which are 
Worthy of attention. The author in the first place gives a resumé of the 
results of Fraunhofer — spectra-of fixed stars, and then quotes 
very briefly from a men Prof. Donati of Florence, which we a ve 
hot seen, and which yecener a the ae ‘tra of Sirius, Vega, Procyon, Reg- 
ulus, Fomalhaut, Castor, Atair, Capra, Arcturus, Pollux, Aldebaran, 
Rigel, and Antares From _ observations . appears ‘niece, ac- 
posting with a face of 19 lines resolved D into three lines. When 
eleven prisms were used, with an angle of about 480°, D was resolved 
into sei lines. The vated expects that great advantage will result 
crease in the size of the prisms and telescopes, ‘and proposes 
to area in that direction— Pogg. Ann., exvii, 654, Dec. 1862. 
Ww. G. 
nee Prof. Rood’s article on Merz’s results, p. 356 this volume.— 
4. A new Spectroscope—Littrow has devised a new form of s 
a in which only one telescope is necessary, and in which four prisms 
made to give the same dispersion as ei ht with the old eed eee 
“* this instrument the bundle of rays which diverge from th @ slit are 
rendered parallel in the usual manner by an achromatic lens ikon at 
ah eh end of the oo telescope a rays then traverse 
rn be whole spectrum can = brought a pmagevie into the eke of 
: also 
nap. | 
been dearibet though very obscurely, by Janssen.’ The adjustment of 
. the prisms in Littrow’s apparatus ought to be adopted in all wpe eogerat opes 
aC = which more than one prism is employed .— Cosmos, xxi 
* Comptes Rendus, June 23d, 1862. 
Wie Jour. Sct.—Srconp Sexes, Vor. XXXV, No. 105.—Mar, 1863. 
53 
Ww. G. 
