292 Scientific Proceedings, Royal Dublin Society. 
work done by Dr. Eder in 1890, it would have been a pleasure to 
have recognised it with that of other investigators whose works 
were mentioned. 
In justice to the paper criticised, however, it may be mentioned, 
first, that with the same dispersive power the method of operating 
adopted by me made it evident that there were more lines and 
bands than occur in Eder and Valenta’s spectrum. Thus in 
Lecoeq de Boisbaudran’s 6 group I observed 12 lines or bands: 
they measured but 3. 
The respective measurements are here given :— 
Ed d Valenta. 
| Hartley, | fderand Valenta, 
5473 5471 
Yellow, . . 5446 5442 ‘ Yellow. 
5422 5423 
They designated this the B band. 
Between the 6 and the y group I have given ten measure- 
ments: they give four. 
I quote their numbers and mine, with those of others, for 
comparison :— 
[ Ed d Val ae 
TRINA IEE (Gaal atyasston) Pee RK 
5193 oe s a 
5170 5765 5165-50 Watts. us 
5138-56 
5138 5129 5138-40 Fievez. a8 YK eR, 
5138-13 
Ee Watts. 
5098 5096 5097-90 Fievez, |) 5098-34 
| 5098-19 \ KG R. 
Green, .<| 5086 5084 5086-90 Fievez. eae \K.&R. 
| 4952 a 4951-5 
|| 4899 ee so | 
ayser 
|| 4816 ph 4815-66 $ and fe: 
Runge 
| 4774 = 4175082 | me 
\| 4765 bis 4763-86 J 
