Thcrc is discordant information in the iitcrnturc on the composition of the zirconium-nr&nnro complex in solution. A dctailcd spoctrophotomctric study indicatc?n thst nt p?r 1.3, 1.7 and 3.5 the complex is formed by one mole of zirconium rcncting with one rnolc of nrscnazo (Ii), giving the empirical formula %rR. Lcs auteurs ont cffcctuc! une Qtudc spuctrophotom&rique sur la composition du complcxc circonium-arsdnaxo cn solution. Aux pN f .3, x.7 ct 3.5, Ic complclxc cst form4 d'unc mole dc zirconium ct d'une moic ii'arsdnolzo (R), donnnnt In formulc cmpiriquc %rR. In dcr Litcrntur wcrdcn widcrsprcchcndc Angzrben iibcr die %us~mntcnsctzung des Zirkonium-Arsctlnzo-Iiomplcxcs in L(isung gemacht. Einc eingchende spcktralphotomctrischc Untersuchung zcigt, class hcim pH-Wcrt 1~3, x-7 und 3.5 &r Komplcx ws cincm Mol Xirkonium und cinem Mel Arsen;rzo gcbildct wird. REPERE3NCBS * V. 1. ICuz~re~sov. I,. hl. I~UPANOVA ANDY. V. MATROSOVA, %auadsk. Lut,, 22 (r~gG) 4oG, a h. F. 1\2~~~5I~~K0v,%a~~dsk. tab.. 24 (rgfj8) 1050. 3 S. %IBATA. Y. ~SIIGURO AND 'r. bfATSUMA*,, ~nut.C!rina, Aela, 23 (igbo) 384. -* S. SHX~&TA. Y, IsHrc;uao ANI 'r. %'hTSURlAE, ivugoya Kogyo Gijtrisu Sfrittensho f-lohoktr, f) (IsGo) * J. S.PHXTZ AND M. JoHNsoN-RIcIIAHD,A~~(L~.G~~~. Acfa, za(195g) xG4.