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ment. Small amounts of lanthanum would, of course, considerably alter the apparent equivalent weight of yttrium. The spectrum lines of lant'hanum are, contrary to those of samarium and gadolinium, quite readily distinguished from those of yttrium, but none of the lines is visible beyond 0.1 per cent. The persistpt lilies are a t 4333.8, 4086.7, 3993.8! 3988.5, and 3949.1 A. Acknowledgment
Tlie author desires t o thank B. S. Hopkiiis, in w l r c w laboratory this work was clone, for permission to 1.14~ apparatus
Yo]. 2,
KO.
1
and niaterials required during the investigation. He also wishes to thank R . K. Ball for yaluable advice received during the course of the xork. Literature Cited (1) Freed, Phsr Rea., 34, 945 (1929). ( 2 ) g a p e r , "Tabelle der Hauptlinien der Linienspektra. aller Elemente."
Springer, 1926. ( 3 ) I.o\re, "Atlas der letzteri Linien der wichstigsten Elemente," Steinkopff, 1928. (4) Quill and Selwood, ISO. ESG. C I I ~ K Anal. , Ed., 1, 180 (1929). ( 5 ) Twyman, "lvave Length Tab!es for Spectrum .%naIysi5," Hilger, 1923.
A Simplified Goodrich Plastometer' E. Karrer, J . 11. Davies, and E. 0. Dieterich THE13. F. GOGDRICH Cosip.ksu, A K R O N ,OHIO
S RECEST paper>
R A simplified form of the Goodrich plastometer, for Val Inay also be lead florn factory-control use, is described and its use in measurtIie gage. Tlle softness arid new definition of phsticity ( 2 ) was set tort11 ing plasticity is discussed. This is accomplished by letentirity a r e c a l c u l a t e d a n d a p o w e r - d r i v e n plasmeasuring the softness and the retentivity of the rubfroln the dial rpadillgs a t the tometer (3) for measuring the her, since plasticity has beell shown to be made up of end of tile collipreA
