MAPPING ABSORPTION SPECTRA OF VARIOUS SALTS. 



49 



to X 3540, X 3550 very weak, X 3570 very weak, X 3600 to X 3660, X 3720 very 

 weak and wide, X 3770 weak, X 3800 (about 20 Angstrom units wide), X 3860 

 to X 3945, X 3970, X 4050, X 4070, X 4320 very wide and weak, X 4540 (about 

 40 Angstrom units wide) ; X 4640 to X 4750 is a region consisting of two diffuse 

 bands that practically run together, X 4800 weak, X 5110 weak. Other bands 

 appear in the region of longer wave-lengths, but they are very weak. 



A 100-mm. strip showed complete absorption of wave-lengths shorter 

 than X 4130. Bands appeared from X 4210 to X 4370; a band about 30 Ang- 

 strom units wide at X 4420; a band from X 4470 to X 4840, X 4890 to X 4950, 

 X 4200, X 4230 (these two bands are of about the same intensity, rather dif- 

 fuse and about 20 Angstrom units wide), X 5500, X 5525; these bands are very 

 similar to the preceding pair, being, however, considerably more intense. 



1 Spectres Lumineux, Paris bei Gauthier-Villars (1S74). 



2 Journ. de Phys., 2, 446 (1883). 



3Bih. K. Svensk.Vet.-Ak. Handl., 2S, n. Nr. 1 (1902). 



4 Zeit. angew. Chemie., 15, 1282 (1902). 

 5 Die qualitative Spectralanalyse anorganischer Korper, 

 Berlin bei Muckenberger (1900). 



Samarium Nitrate in Water. 

 The absorption spectrum of samarium nitrate in water is given in A, 

 plate 33. The absorption bands have almost the same characteristics, rela- 

 tive intensity, wave-lengths, etc., that water-bands of samarium chloride have. 



Samarium Chloride in Methyl and Ethyl Alcohols. 



The absorption spectrum of samarium chloride in methyl alcohol, B, 

 plate 32, is so similar to the absorption of this salt in ethyl alcohol, A, plate 

 34, that only the former will be described in detail. It will be seen from the 

 spectrograms that the general absorption in the ultra-violet and violet in 

 the case of the ethyl alcohol solution is very much greater than in the case 

 of the methyl alcohol solution. 



B, plate 32, represents the absorption of a normal solution of sama- 

 rium chloride in methyl alcohol, the depths of all being 2, 5, 9, 18, 27, and 

 27 mm. The last spark spectrum was taken with the solution removed simply 



