The Powers of the Philosopher’s Stone.
§ 26. The alchemists believed that a most minute proportion of the Stone projected upon considerable quantities of heated mercury, molten lead, or other “base” metal, would transmute practically the whole into silver or gold. This claim of the alchemists, that a most minute quantity of the Stone was sufficient to transmute considerable quantities of “base” metal, has been the object of much ridicule. Certainly, some of the claims of the alchemists (understood literally) are out of all reason; but on the other hand, the disproportion between the quantities of Stone and transmuted metal cannot be advanced as an à priori objection to the alchemists’ claims, inasmuch that a class of chemical reactions (called “catalytic”) is known, in which the presence of a small quantity of some appropriate form of matter—the catalyst—brings about a chemical change in an indefinite quantity of some other form or forms; thus, for example, cane-sugar in aqueous solution is converted into two other sugars by the action of small quantities of acid; and sulphur-dioxide and oxygen, which will not combine under ordinary conditions, do so readily in the presence of a small quantity of platinized asbestos, which is obtained unaltered after the reaction is completed and may be used over and over again (this process is actually employed in the manufacture of sulphuric acid or oil of vitriol). However, whether any such catalytic transmutation of the chemical “elements” is possible is merely conjecture.