 Berthollet didn’t accept this rigid distinction between solutions and compounds. He believed that whenever a substance is brought into contact with another, it forms a homogeneous union until further addition of the substance leaves the union in excess. For example, when water and sugar are combined, they initially form a homogenous union. At a certain point, the affinities of water and sugar for one another are saturated, and a second phase of solid sugar will form upon the addition of more sugar. This point of saturation will vary with the pressure and temperature of the solution. Berthollet maintained that just as the amount of sugar in a saturated solution varies with temperature and pressure, the proportions of elements in compounds are sensitive to ambient conditions. Thus, he argued, it is not true that substances are always composed of the same proportions of the element and this undermines the law of constant proportions. But after a lengthy debate, chemists came to accept that the evidence Proust adduced established the law of constant proportions for compounds, which were thereby distinguished from solutions.