356 REPORT—1899. 
alkyl radicals are substituted for hydrogen. The spectra of methyl- 
carbostyril differ in a marked manner from those of carbostyril and 
methylpseudocarbostyril ; the absorption band occupies a different 
position, is less persistent and less intense than the corresponding band 
of the latter, and the amount of the general absorption is less. Isatin 
Scales of Oscillation Frequencies. 
3000 35000 3000 
10 20 30 40 50 60 70 80 90 
a Gi Sars 
8 3 HEH Eat 
Say Peal (aS oli SESRSESE 
wm > HE REE ES SES isan aeee 
ort FRRE ISRO OTE ee || 
eee Min Ce eS aaR eS 
30 Pee ces eee 
8 BE Eh BRB bic Se) ia aeeee 
[Ty 1 RS Bee eee eee 
Bei BE GHP BERE ANSE PARES 
_ 20 Oe ee ee eee ee 
Sak ED aaa RIRRE) CHEAE See EEE 
8 ee BEGET BERL 
ee et ae | a ee ETE 
= 8 bleeds CC Saree ee 
co 2 ee ee © 
Ene. cee ee ieee ae 
/ oe eee 
DER ERE. BES oe) See BSR. 
Pq | od Sa a ee aT SL a ar 
URE REELS Be Se cab Sue ee 
SERED REC Ree Ce RE RESeeee 
Methylearbostyril. Carbostyril. Methylpseudocarbostyr il. 
Curves of Molecular Vibrations. 
and its derivatives show similar relations. In the spectra of isatin there 
are two absorption bands. The spectra of methylpseudoisatin closely 
resemble those of isatin, likewise exhibiting two absorption bands and 
about the same extent of general absorption. Jn methylisatin there is 
only one strong absorption band. 
The very close resemblance between the curves of molecular absorp- 
tion of carbostyril and methyl- and ethylpseudocarbostyril, and between 
those of isatin and methylpseudoisatin, point to identity of constitution, 
and, inasmuch as the chemical behaviour of methylpseudocarbostyril and 
methylpseudoisatin show that these compounds are lactams, the lactam 
constitution must also be assigned to carbostyril and isatin. This con- 
clusion agrees with that arrived at by Goldschmidt and Meissler,’ who 
employed a purely chemical method in their investigations, and also with 
the more recent results of Knorr.* 
» Ber., 1890, vol. xxiii. p, 253. 2 Annalen, 1896, vol. ecxciii. p. 81. 
