During the first half of 1808, Davy conducted a series of further electrolysis experiments on alkaline earths including lime, magnesia, strontites and barytes. At the beginning of June, Davy received a letter from the Swedish chemist Berzelius claiming that he, in conjunction with Dr. Pontin, had successfully obtained amalgams of calcium and barium by electrolysing lime and barytes using a mercury cathode. Davy managed to successfully repeat these experiments almost immediately and expanded Berzelius' method to strontites and magnesia. He noted that while these amalgams oxidized in only a few minutes when exposed to air they could be preserved for lengthy periods of time when submerged in naphtha before becoming covered with a white crust.