3 
os 
or 
ABSORPTION SPECTRA AND’ CHEMICAL CONSTITUTION. 
Pyridine. 
1 mill. mol. in 20 e.c. alcohol. 
With 5, 4, 3, 2, and 1 mm. there is complete absorption beyond !/\ 
3647. 
1 mill. mol. in 100 e.c. alcohol. 
With 5, 4, 3, 2, and 1 mm. an absorption band appears from !/\ 
3707 to 4426-7. 
1 mill. mol. in 500 e.c. alcohol. 
With 5, 4 and 3 mm. the absorption band appears from !/\ 3768 to 
4253. With 2 and 1 mm. the absorption band disappears and the 
spectrum is continuous to 1/A 4566, but weak towards the violet end. 
Pyridine and HCl. 
1155 gram hydrochloride in 40 c.c. alcohol. 
Double thicknesses of cells taken. With 10, 8, and 6 mm. the spec- 
trum was continuous to'/A 3611. With 4 and 2mm. an absorption band 
appeared from 1/\ 3647 to 4426-7. 
1155 gram hydrochloride in 200 c.e. alcohol. 
With 10 mm. the absorption band appears from !/\ 3467 to \ 4426°7. 
With 8, 6, 4, and 2 mm. the absorption band is still seen, but it gets 
narrower as the thickness of the layer of liquid is diminished. 
"1155 gram hydrochloride in 1,000 ¢.c. alcohol. 
With 10 mm. absorption band appears from !/A 3762 to 4125, and 
it persists until a thickness of 6 mm. is reached. With 4 mm. the 
absorption band disappears, and with 2 mm. the continuous spectrum is 
obtained. 
Dipyridine. 
158 gram in 1,000 c.c. alcohol. 
With 5, 4, 3, and 2 mm. the spectrum is continuous to 1/\ 3580. 
With 2 mm. there is a prolongation '/A 3890. With 1mm. an absorption 
band appears from '/\ 3890 to 4331. 
158 gram in 5,000 c.c. alcohol. 
With 5 mm. there is an absorption band from 1/\ 3890 to 4331. 
With 4 mm. the absorption band disappears and the spectrum extends 
to !/\ 4543, 
Picoline.* 
094 gram in 20 c.c. alcohol. 
With 5and 4 mm. the spectrum is continuous to !/\ 3537, and with 
5 and 2 mm. to'/\ 3556. With 1 mm. an absorption band appears from 
1/ 3580 to 4331. 
094 gram in 100 ¢.c. alcohol. 
With 5, 4, 3, 2, and 1 mm. the absorption band appears from !/) 
3580 to 4331. With 1 mm. the band is slightly narrower. 
094 gram in 500 c.c. alcohol. 
With 5, 4, 3, and 2 mm. the absorption band appears from !/ 
3647 to 4331. With 1 mm. the absorption band has disappeared and 
the spectrum ends at 1/\ 4560. 
See also Trans. Chem. Soc. February 1882. 
