Three glaciogenic cloud seeding experiments with Silver Iodide (AgI) have been completed in Israel since the 1960's. These experiments claimed 12-15% rain enhancement in the catchment area of the Sea of Galilee, around 20-25 km downwind of the seeding line. However, the seeding efficiency has been debated, and several studies have challenged this claim [Gagin, 1975; Gagin and Neumann, 1981; Rangno and Hobbs, 1995; Levi and Rosenfeld, 1996; Levin et al., 2010]. This prompted the fourth seeding experiment ("Israel-4"), which is still ongoing. As part of Israel-4 experiment, we sampled precipitation in northern Israel for chemical analysis in order to obtain information on the aerosols' load in air masses. This data was combined with information on cloud properties retrieved from the METEOSAT geostationary satellite. Seeding effect was examined by comparing cloud properties (cloud top phase (CTP) and cloud top temperature (CTT) and by comparing Ag concentrations and enrichments between seeded and unseeded clouds. This comparison was done for different air masses detected by the method detailed in Zipori et al [2015]. Our results show that AgI reached the target area, as Ag/Al and Ag/Na values were higher in seeded rain samples, especially in samples collected during marine air masses relative to unseeded rain. In addition, our results show that AgI has the strongest impact on marine clouds probably because these clouds have low ice nuclei concentrations. This work provides a physical evidence for the seeding impact, and should help sorting out the ongoing debate on this subject.