After the downy mildew had struck, botany professor Pierre-Marie-Alexis Millardet of the University of Bordeaux studied the disease in vineyards of the Bordeaux region. Millardet then noted that vines closest to the roads did not show mildew, while all other vines were affected. After inquiries, he found out those vines had been sprayed with a mixture of CuSO4 and lime to deter passersby from eating the grapes, since this treatment was both visible and bitter-tasting. This led Millardet to conduct trials with this treatment. The trials primarily took place in the vineyards of Château Dauzac, where he was assisted by Ernest David, Dauzac's technical director. Millardet published his findings in 1885, and recommended the mixture to combat downy mildew.