

CHEMISTRY. 635 



on May 31, 1SS3, under the above title, and presented a novel and re- 

 markable extension of investigations into the phenomena of radiant 

 matter with which his name is identified. 



Many substances when struck by the molecular discharge from the 

 negative pole in a highly exhausted tube emit phosphorescent light, 

 some faintly and others with great intensity. On examining tho emitted 

 light in the spectroscope most bodies gave a faint continuous spectrum, 

 and more rarely the spectrum of the phosphorescent light is discon- 

 tinuous. Especial attention has been directed to the latter phenomenon. 

 After a long and laborious search for an unknown substance which gave 

 under the above conditions a bright citron-colored band or line, Crookes 

 found it belonged to yttrium. In the course of his investigations he 

 worked up 10 pounds of North Carolina zircons, 2 pounds of oraugite 

 and thorite and about 15 pounds of Xorth Carolina samarskite, review* 

 ing the characteristics of all the rare earths known to exist in these min- 

 erals and those awaiting confirmation. Crookes finally narrowed the 

 elusive substance down to yttrium, the spectrum of which in a radiant 

 matter tube is very beautiful, consisting of an intensely brilliant citron 

 band and two bright green bands together with fainter lines not charac- 

 teristic. The best results are obtained with the sulphate ; pure yttria 

 precipitated by ammonia does not phosphoresce in the slightest degree. 



The extraordinary delicacy of this new test for yttrium is such that 

 the element was detected when present in one-millionth part. Crookes 

 found in pink coral 1 part of yttrium in 200 parts; strontianite contains 

 1 in 500 ; calcite 1 in 10,000 ; ox bone 1 in 10,000 ; an earthy meteorite 

 1 in 100,000 ; and tobacco ash 1 part in 1,000,000. The wide distribution 

 of yttrium is notable. (Chem. Neics, xlvii, 2G1.) 



Relation between the Composition and Absorption Spectra of Organic 

 Bodies. — Gerhard Kriiss and S. CEcouomides have examined the ab- 

 sorption spectra of indigo and its methyl, ethyl, nitro-and amitlo-de- 

 rivatives, with a view to determining the relation between chemical 

 composition and absorption spectra. They conclude that the introduc- 

 tion of methyl, oxymethyl, ethyl, and bromine in the place of an atom 

 of hydrogen moves the absorption bands to tho less refrangible end of 

 the spectrum, and the introduction of the nitro and amido groups has 

 an opposite effect. The apparatus employed was the universal spec- 

 troscope, by A. Kriiss of Hanover, having fine adjustments. (Ber. d. 

 chem. Ges., xvi, 2051.) 



INORGANIC. 



Boron. — The substances obtained by the action of aluminium on boric 

 acid at a very high temperature have been variously described by 

 chemists; Deville and Wohler obtained yellowish or reddish regular 

 octahedra, containing variable proportions of carbon and of alumin- 

 ium, together with lustrous black scales or plates containing 2.4 per 

 cent, carbon. On the other hand, Hampe assigned to the black crystal- 



