ANALYTICAL CHEMISTRY
1546 procedure, may exist to the extent of perhaps 0.00005% without being observed above background. ACKNOWLEDGMENT
The authors wish to express their appreciation to E. R. Morgan and J. C. Shyne, Scientific Laboratory, Metallurgy Department, Ford Motor co.,for directing the preparation of the standard steels. LITERATURE CITED
( I ) Corljss, c. H., and Scribner, B. F., J . Research S a t l . Blcr. S t a d Urds, 36,351-64 (1946) (2) Dieke, G..H., “Studs of Standard Methods for Spectrographic
Analysis,” War Production Board Report W-90 (March 20, 1944). (3) Hasler, M. F., and Dietert. H. W., J . O p t . SOC.Arner., 33, 218-22 (1943). (4) Irish, P. R.. Ibid., 35, 226--33 (1945). (5) Irish, P. R.. Steel, 113, 100~-5,127-30 (1943). (6) Kirchgessner, W. G.. and Findelstein, 5 . .i., AS.
