EXPERIMENT STATION BULLETINS. 439 



cornutus. Then the extract was pressed out through Swiss muslin. The 

 crude extract obtained in this way was whitish or creamy in appearance, 

 at first, due to fat and very tiny particles of tissue which came 

 through the muslin. When this extract was filtered through 

 heavy filters under twenty to twenty-five pounds pressure, a clear or 

 slightly straw-colored filtrate was obtained, and (on the filter) a con- 

 siderable residue. When either the crude extract or the filtrate was 

 allowed to stand for a time, the surface in contact with the air turned 

 dark while the deeper parts of the fluid remained as at first for hours — 

 for more than a day if kept cool or treated with a little of some weak 

 antiseptic like chloroform, sodium fluoride solution, toluol or ether. 

 Whenever work with the extract extended over several hours, some such 

 antiseptic was used provided the nature of the experiment would permit. 

 If to about 1 c. c. of the crude extract a few (2 to 5) drops of a saturated 

 solution of alcoholic guaiac were added, the milky mixture would begin 

 to show a tinge of blue within one or two minutes, and would gradually 

 develop a beautiful deep blue coloration. When about 1 c. c. of a stand- 

 ard hydroquinone solution* was added to 3 c. c. of the extract, it slowly 

 began to turn reddish brown; and after several hours, the entire mixture 

 appeared very dark brown or perhaps almost black, giv'ing off a decided 

 odor of quinone. Vernon's alpha-naphthol paraphenylene-diamine mix- 

 ture! was tried, and this, the crude extract rapidly oxidized to the blue 

 indophenol. Finally, the extract was able to slowly oxidize tyrosine 

 (Merck) until after a few hours one obtained a heavy black or melanic 

 pigment. It was interesting to drop a small pinch of tyrosine crystals 

 into a little extract from P. cornutus tissue, and then watch the black 

 coloration develop about it. The extract clearly possessed oxidasic prop- 

 erties. Moreover, the filtrate and the washed residue left from filtering 

 the crude extract under pressure gave the reactions showing the presence 

 of oxidases. That is, oxidases soluble in water and insoluble in water 

 were present. Likewise two catalases, one soluble in water and going 

 with the filtrate, the other insoluble in water and remaining in the 

 washed residue, were found to be present as first described by LoewJ in 

 the tobacco plant, and both were very active in liberating bubbles of 

 oxygen from hydrogen peroxide. 



Some of the fresh extract which had just darkened was confined in 

 the absence of oxygen, and it became rapidly changed back to the appear- 

 ance it had before it had darkened. If a few drops of a methylene blue 

 solution were added to some of the extract and then the latter were con- 

 fined from the oxygen of the air, the blue color became entirely reduced. 

 Eeducing bodies, therefore, seemed to be present; and besides, the re- 

 duction of methylene blue took place whether it was confined with the 

 filtrate of the crude extract or with the washed residue. Thus, oxidases, 

 catalases, and reducing bodies were all found to exist in the pulp and in 

 the crude water extract of P. cornutus in two forms, one being soluble 

 and the other insoluble in water. It therefore seemed desirable to make 



♦This standard solution was made up by dissolving 1.1 grams of hydroquinone in 100 c. c. 

 of distilled water. 



m 

 (i. e. — hydroquinone.) 

 10 

 tVernon, H. M. The Quantitative estimation of Indophenol Oxidase of Animal Tissues. 

 The Journal of Physiology, Vol. XLII., Nos. 5 and 6. pp. 402-427. 



tOscar Loew : Report No. 68 Div. of Veg. Phys. and Path., U. S. Dept. of Agr., 1901. 



