416 



SCIENCE 



[N. S. Vol. XXXVI. No. 92S 



to ultraviolet light, about two thirds of these compounds reflect ultraviolet light about as 



vrhite substances, when immerged in such they reflect ordinary light, 



light, would appear to us as black or dark The writer was unable to find any constant 



gray. As a rule inorganic compounds do not relation between the chemical constitution or 



1 l__U 



_ _ ^„- _ 



1 ' I 



. _ it .- ? 1 _ , 



Chi I . I I c ' ii I 111 ii u . L || ji , II „ i!,oi.,^.. ', 



,Arb»^'F t\ila\mi-t G-i^fnp^ HiMiiboftiiia. Acoiiibua. Veratnns. 



Tiieahrontini CdFeina Stryhwna Bructna,. Bcrhcnna jAsparasma 



rbutma fyiamiiia ElattPina.' Hclltborf.iia...' Aco«i{j(tt. -' Vetatriiu. 



seem to behave in such an extraordinary 

 manner. Excepting zinc oxyde which, as 

 Professor Wood has shown, powerfully absorbs 

 ultraviolet light, and bismuth sub-nitrate 

 which, as the writer and Professor Tristan 

 have found, reflects but little more ultra- 

 violet light than zinc oxide, most inorganic 



physical properties of the 24 substances and 

 their selective reflection for ultraviolet light. 

 The tremendous difi^erences shown on the 

 two photographs will probably one day find 

 some application to analytical chemistry. 



GUSTAVE MiOHAUD 



Costa Eica State College 



