266 
great persistency ; and the lines marked y and w show well in the 
original negatives in those dilutions. 
Scientific Proceedings, Royal Dublin Society. 
QUANTITATIVE SrEcrruM oF LANTHANUM CHLORIDE. 
Linear : Tytenniee Linear 
Measure- Wave- J Measure- Wave- 
ment, length. Danes eR length. 
zoo mech. zoo inch. 
247°5 5088-6 6 x | 341:1 3898-0 
251°5 5465°4 8 x 351°6 3791-0 
254-6 5877°3 8" @ 354-7 3759-2 
273°8 4921-1 10” x 373°3 3586-7 
274:°7 4901-1 10 x 382°0 8517°3 
280-0 4792°8 Au No. 9 399°4 3383°0 
282°6 4743°3 8 405-0 3344°7 
285:2 4692°7 8 406-0 3337°6 
286°8 4663°9 46 411-0 3718-0 
287°3 4655°7 8 > 432-0 3171°8 
294°8 4522°6 8 x 501°9 2825°6 
296°9 4488-4 Au No. 10 506-1 2808-4 
300-6 4430-1 8 > 535°6 2695°6 
306-9 4333-9 15” 538°5 2685°1 
308-1 4315°4 Au No. 11 548-1 2651°8 
309°5 4296-2 8 560°5 2610°5 
310-1 4287°1 20 @ 566-9 2590°2 
3114 4269°7 10 ¢ 364-2 2641°6 
311°8 4263°7 8 379°9 2596°2 
313°5 4238°5 10 392°8 2560°5 
316°7 4196-7 10 408-5 2519°3 
822°1 4123-4 30 @ 491-2 2487-6 
325°8 4077°5 15 @ 425°7 2476-8 
326°7 4065-2 Au No. 12 | 446°3 2428-1 
329°5 4031°8 20 » 459-0 2399°7 
303°2 3988-7 30 x 468°3 2379°5 
336°6 3949°3 50 w 509-0 2297-9 
Intensity 
and 
Persistency. 
Au No. 13 
50 
20 » 
Au No. 14 
50 o 
Au No. 15 
8% 
15 @ 
20y 
Au No. 20 
3 XxX 
1¢ 
1¢ 
8» 
ax 
Au No. 24 
Au No. 23 
