The viscosity of (Ag-Me)NO, systems are reported, where Me = Li, Na, K, Rb, Cs. Whereas the viscosity of (Ag-Na)NO, system varies nearly linearly with composition, the viscosity of the other mixtures shows the usual negative deviations from additivity. The observed A17 in (Ag-Me)NO, systems could be accounted for by the same factors which govern the solution properties of alkali nitrate mixtures. They were found to obey the semi-empirical equation A7 = 3.482 x 1W8(r1 -r,)x,x,e rose'r if 'As+ is taken as 0% A. This circumstance is discussed. R6suaxt6 -On a etudie la viscosit6 de melanges binaires (Ag-Me)NO, oti Me = Li, Na, K, Rb, Cs. Tandis que la viscosid du +&me (Ag-Na)NO, est une fonction lindaire de la composition, les autres syst&mes presentent des &carts ordinairs de l'additivit& On a constat que les dkviations Aq dans les syst&mes (Ag-Me)NO, sont gouvem&s par les mgmes facteurs que dans les m&mges de nitrates alcalins. Les d&iations de l'additivitd obeissent a 1'6quation AT = 3,482 x 10-B(rl -r&x1x, e408f'T si l'on considke que rAr+ = 0,% A. On discute cette CirCOnStmC& Zusammenfassvng-Man hat die ViskositSit der bin5ren Salzmischungen (Ag-Me) NO, wo Me = Li, Na, K, Rb, Cs ist, untersucht. Die Viskositiit des (Ag-Na)NO, Systems ist eiue lineare Funktion der Komposition. Die anderen Systeme zeigen negative Abuseichungen gegeniiber der Linearitiit. Die Abweichungen Ag der (Ag-Me)NO, Systeme sind von denselben Faktoren abhiingig, wie in den geschmolzehen Alkalinitratmischungen. Die Abweichungen gegeniiber der Linear&&t sind durch die Gieichung A3 = 3,482 . IO-' (rl -rz)x1xle40**'~, ist diskutiert. wo raa+ = 0,95 A ist, gegeben. Dieser Umstand IN THE previous papers1s2 we have published a detailed report on the viscosity in the ten fused binary systems formed by the alkali nitrates. In the present paper we extend our study of viscc)sity to the binary mixtures of silver nitrate with alkali nitrates, (Ag-Me)NO, WI tere Me = Li, Na, K, Rb, Cs, for which no data are available in the literature.