Alumen and Alumina: This remedy comes in very nicely after Alumen, which has much Alumina in its nature and depends largely upon Alumina, which is its base, for its way of working. It occurs to me to throw out a little hint. When you have a good substantial proving of an oxide or a carbonate, and the mental symptoms are well brought out, you can use these, in a measure in a presumptive way, in prescribing another salt, with the same base, which has a few mental symptoms in its proving. For instance, you have a group of symptoms decidedly relating to Alumen. The mental symptoms of Alumen, however, have not been brought out to any extent, but still you have the mental symptoms of the base of Alumen, which is the oxide, so that if the patient has the mental symptoms of Alumina and the physical symptoms of Alumen, you can rationally presume that Alumen will cure because of the Aluminum in each.