CATALYSIS
We now come to a remarkable series of chemical phenomena, which have been much studied during the past century, and which have a bearing upon both organic and inorganic chemistry. More than a century ago, it was discovered that certain chemical substances, which will not normally combine with one another, can be made to do so, if another substance is brought into contact with them. This third substance does not in any way enter into the combination, or share in the reaction; its mere presence seems to bring it about. Thus, oxygen and hydrogen may be mixed together; but if a small amount of “platinum black” be introduced, an explosion of the gases at once occurs. Hydroperoxide is rapidly split into oxygen and water when in contact with “platinum black,” etc. These contact-effects are very curious, and have engaged the attention of chemists for a long time. Berzelius is responsible for the term now generally used—catalysis. We now speak of catalytic power, catalytic reactions, and so forth.
These catalytic reäctions soon became very important factors in organic chemistry and biology, as well as in the field of inorganic chemistry. In 1833, Payen and Persoz in Paris made the discovery that germinating seeds contain a peculiar contact-substance, which transforms starch into sugar. This substance they namedDiastase. Similar effects were noted to occur elsewhere,—particularly in the protein digestion in the stomach of man and the higher animals. We now know that many such reäctions occur in the living cells, and the chemical phenomena of life have had an entirely new light thrown upon them by these findings.