210 
MESSES. EOSCOE AND THOEPE ON THE ABSOEPTION-SPECTEA 
I. Absorption-Spectrum of Bromine. 
Colour of rays. 
Wave-lengths 
Colour of rays. 
Wave-lengths. 
Remarks. 
Eed 
Orange ...<^ 
6801-3 
6777-2 
6723-9 
6649-1 
6381-3 
6526-9 
6468-9 
6455-4 
6413-0 
6401-0 
6372-6 
6350-5 
6336 7 
6312-1 
6292-8 
6275-4 
6263-9 
6240-2 
6223-3 
6190-9 
6169-7 
6144-1 
6119-0 
6101-4 
6072-2 
6053-2 
6027-3 
6006-1 
5987-5 
5956-5 
5945-1 
5913-9 
5905-9 
5875-5 
5870-7 
/• 
S, 
S' 
f 
s. 
f 
v.f. 
Yellow ...<^ 
Green 4 
5835-3 
5797-7 
5762-7 
5727-5 
5694-4 
5660-4 
5634-8 
5624-4 
5592-0 
5580-6 
5560-7 
5556-8 
5534-1 
5510-3 
5501-3 
5483-8 
5476-8 
5460-1 
5439-9 
5418-2 
5403-2 
5380-3 
5365-8 
5347-5 
5337-4 
5306-8 
5298-7 
5292-2 
5274-5 
5258-8 
5244-1 
/• 
s. 
/- 
Absorption- Spectrum of Iodine Monochloride. 
This compound was prepared by heating a mixture of iodine and finely powdered 
potassium chlorate. After repeated distillation from potassium chlorate it boiled 
constantly between 99 0- 7 and 100°*7. Corrected and reduced barometer 744‘3 millims. 
The spectrum of iodine monochloride is likewise a channelled one, generally resem- 
bling that of bromine, but differing essentially from it as well in the position of the 
bands as in their distribution. For the purpose of mapping its absorption-spectrum the 
chloride was placed in a cylindrical glass tube, 14 centims. in length, having flattened 
ends, the rays from the lime-light passing through the length of the tube, which was 
then heated with a lamp. 
The spectra of the moderately heated and strongly heated vapour exhibit differences 
similar to those seen in the case of bromine. Thus at the higher temperature a great 
