AND ANTI-ENZYMES 107 



grm. hydrocyanic acid per cubic centimetre to a colloidal platinum 

 solution containing 0000,006 grm. platinum per cubic centimetre 

 reduced the intense action of the platinsol upon hydrogen per- 

 oxide to half its original value. Here it is to be noted that 

 although the quantities of both platinum and hydrocyanic acid are 

 small, that of the platinum is 6000 times as large as the hydro- 

 cyanic acid ; hence there is no stochiometric relationship, and the 

 action cannot be ascribed to any chemical combination in definite 

 molecular relationship between the colloidal platinum and the 

 hydrocyanic acid. The paralysing effect of the hydrocyanic acid 

 can be removed by passing a stream of air through the solution 

 and so removing the hydrocyanic acid. The " recovery " shows 

 that the catalyst is not destroyed by the " poison " of the anti- 

 catalyst but only inhibited during its presence. 



The catalytic action of platinum upon hydrogen peroxide or 

 water-gas is also anti- catalysed by traces of many substances of 

 which the following list is given by Bredig : Iodine, mercuric 

 chloride, hydrogen sulphide, sodium thio-sulphate, carbon-mon- 

 oxide, phosphorus, hydrogen phosphide, hydrogen arsenide, mer- 

 curic cyanide, carbon-bisulphide. 



In this group must also be placed the anti-ferments or anti- 

 enzymes which have been shown to exist in the case of the majority 

 of the enzymes. These have usually been obtained by the process 

 of injection into an animal of solutions containing the enzyme 

 in question for a period, and then separating the animal's serum 

 and demonstrating that it contains a substance capable of stopping 

 the action of the enzyme. 



The first anti-enzyme was shown to exist by Morgenroth in 

 the case of anti-rennin (" Antilab.") ; he obtained it in a similar 

 fashion to an antitoxin by injection of increasing doses of rennet 

 solution, and found that both the serum and the milk of the in- 

 jected animal possessed in a high degree the power of preventing 

 the coagulation of caseinogen by the action of rennin. Anti- 

 bodies have since been obtained to pepsin, trypsin, fibrin ferment, 

 laccase, urease, and tyrosinase. 



It has been urged that this reaction of the tissue cells to 

 ferments shows that the toxins of disease and various poisons of 

 animal and vegetable source act similarly to enzymes, and produce 

 their effect in a similar catalytic fashion, until their action is 

 paralysed by the production by the tissue cells of the appropriate 



