April 21, 1911] 



SCIENCE 



627 



ing -with lacease prepared from the sap of the 

 lac-tree, and Lindet with an oxidase found in 

 eider and wines, that these enzymes possess the 

 property of oxidizing certain poly-atomic- 

 phenols; e. g., hydroquinone to quinone and 

 pyrogallol to purpurogaUic. Thus the follow- 

 ing experiments were planned to study this 

 property of the enzyme by preparing artificial 

 solutions of gallic acid and albumen and 

 measuring the rate and extent of the forma- 

 tion of the tannin-like bodies by the decrease 

 of the soluble nitrogen. 



Accordingly, 500 c.c. quantities of the fol- 

 lowing solution were prepared: 



No. 1 — gallic acid alone, 4 per cent. 



No. 2 — gallic acid and en2ynie. 



No. 3 — gallic acid and enzyme. 



No. 4 — gallic acid, albumen and enzyme. 



No. 5 — gallic acid, enzyme and albumen. 



No. 6 — en2yme alone. 



The albumen used was a solution of egg 

 white which had been filtered through absorb- 

 ent cotton and contained 1.36 grams of 

 nitrogen per liter. The enzyme was prepared 

 from pear juice by grinding fruit in calcium 

 carbonate, pressing out the juice and allowing 

 it to settle, drawing oflE the supernatant liquid 

 and precipitating the enzyme with 60 per 

 cent, alcohol, collecting on Buchner fiumel, 

 and suspending this precipitate in distilled 

 water. Fifty cubic centimeters of this suspen- 

 sion was used in each case. A series of ex- 

 periments similar in every particular except 

 50 c.c. of 3 per cent, hydrogen peroxide was 

 added in each case, and was carried out in the 

 same time. In about an hour after the 

 enzyme had been added a very heavy floccu- 

 lent precipitate had formed and settled, in 

 those flasks containing all three constituents, 

 viz., gallic acid, albumen and enzyme. Those 

 containing gallic acid and enzyme without 

 albumen had turned a rich wine red color, 

 presumably from the oxidization of the gallic 

 acid. 



Samples of 50 c.c. each were taken after 15 

 hours, and every 24 hours thereafter until 

 there was no longer any decrease in the 

 nitrogen or until the solution showed signs of 

 fermentation. 



Xo. 2. containing gallic acid and albumen, 

 showed no change in soluble nitrogen after 

 5 days. 



No. 4, containing gallic acid, albumen and 

 enzyme, showed a marked decrease in soluble 

 nitrogen amounting to TO per cent, in five and 

 one half days, 26 per cent, being precipitate 

 in the first 15 hours. 



The corresponding solution containing 

 hydrogen peroxide showed a similar decrease, 

 but was considerably more rapid, amounting 

 to 47 per cent, in the first 15 hours. 



Having made this further investigation, as 

 outlined above, thiis determining some of the 

 properties of this oxidizing enzyme and at the 

 same time explaining our former results, it 

 was now desirable to try the effects of this 

 pure enzyme preparation upon certain fungi. 

 Therefore, Cunniiighamiella echinulata, Glom- 

 erella rufomaciilans, Pestalozzia hreviseia and 

 PenicilUum aureiim were used in a quintuple 

 set of experiments according to the method 

 previously referred to, but using the pure 

 oxidase instead of the calcium carbonate pre- 

 cipitate. In all cases there was decided ac- 

 tion increasing with the increased amount of 

 gallic acid or sodium gallate used. 



Since the above experiment showed such 

 high toxic effects which could not all be ac- 

 counted for by the fermentation of the 

 tannin-like body, it was decided to carry out 

 further experiments on the germicidal prop- 

 erties of the solutions formed. It had also 

 been previously noted that the juices that had 

 been prepared by grinding with calcium car- 

 bonate, and in which there was apparently no 

 action of the enzymes fermented much more 

 readily than the juices that had been pre- 

 pared by grinding without calcium carbonate, 

 and it was evident that the other bodies 

 formed in the reaction might have some ger- 

 micidal properties. Accordingly, six days after 

 the experiment with gallic acid to show that 

 the precipitate of the soluble nitrogen had been 

 started, plate cultures on agar-agar and gela- 

 tine were made from the solution containing 

 gallic acid and albumen; gallic acid, enzjone 

 and albumen ; enzsone and albumen. Cultures 

 in beef tea were also made at the same time. 



