590 



SCIENCE 



[N. S. Vol. LII. No. 1355 



its sulphuTj 20 per cent, of its amino nitrogen and 

 changed considerably in its specific rotatory power. 



Biochemistry of plant diseases. Ill Effect of 

 the brown rot fungus on plums: J. J. Willaman 

 and M. Sandstkom. Five varieties of plums were 

 subjected by rotting by Sclerotinia cinerea. The 

 changes in composition of the tissue were charac- 

 terized by (1) an increase in the Pj, values, (2) 

 a decrease in the titre, (3) a decrease in the malic 

 acid, (4) formation of oxalic acid, (5) marked 

 decrease in tannin. The ratio of protein to non- 

 protein nitrogen increases during rotting and dur- 

 ing the ripening of the plums. 



The apparently specific effect of ammonia in the 

 oxidation of butyric acid with hydrogen peroxide: 

 Edgar J. Witzemann. Ammonium butyrate in 

 dilute aqueous solution in the presence or absence 

 of excess ammonium hydroxide is readily oxidized 

 by hydrogen peroxide. Sodium or potassium buty- 

 rate in the presence of absence of excess of the 

 alkali hydroxide is scarcely oxidized at all by hy- 

 drogen peroxide. These facts are of especial in- 

 terest because they offer a new and rational inter- 

 pretation of the interrelation of increased urinary 

 ammonia and increased fat and protein oxidation 

 in acidosis. The fact that large amounts of ace- 

 tone are obtained in this oxidation of ammonium 

 butyrate, as was shown also by Dakin in 1908, sup- 

 ports the application of the results to the interpre- 

 tation of acidosis metabolism. 



Antibody studies — Part 3. A preliminary report 

 on the chemical nature of bacterial antibodies? V. 

 M. HuNTOON, Peter Masucci and E. Hannum. 

 Presented by Peter Masucci. Bacterial suspen- 

 sions were sensitized with specific serum. The 

 protective antibodies were removed from the sen- 

 sitized antigen by various solvents. The resultant 

 solution was filtered through a candle and its pro- 

 tective antibody content determined by the U. S. 

 Hygienic Laboratory method for testing the potency 

 of anti-pneumococcus serum. Direct and indirect 

 chemical methods as well as biological methods 

 used show that protective antibodies are colloidal 

 in nature, are not soluble in ether, and do not 

 belong to the globulin group of serum proteins. 

 They are not destroyed by the action of trypsin 

 over long periods of time, and are not affected by 

 certain dilute acids and alkalies or 30 per cent, 

 sodium chloride solution. Heat above 60° C. pro- 

 gressively destroys or alters their nature. "We may 

 state that antibodies do not belong to that group 

 of proteins usually considered under the head of 

 serum proteins. 



The non-catalase decomposition of hydrogen, per- 

 oxide by aromatic hydrocarbons and their derive^ 

 tives: Sergitjs Morgdlis and Victor E. Levine. 

 The experiments arose from the accidental obser- 

 vation that an enzyme preparation preserved with 

 toluene had acquired a remarkably increased ca- 

 pacity for decomposing hydrogen peroxide. Euler 

 and Blix have recently published the fact that 

 yeast catalase is activated by toluene. The idea 

 of an activation of the enzyme by toluol seems en- 

 tirely improbable, for we have found that toluene 

 alone even in minute quantities decomposes hy- 

 drogen peroxidei The action of toluene is also 

 characteristic of other hydrocarbons of the benzene 

 group. These compounds form a series, accord- 

 ing to the number of methyl radicles attached to 

 the ring, with a gradually decreasing power to 

 decompose hydrogen peroxide, thus Benzene > To- 

 luene > Xyluene > Mesitylene. The reaction is not 

 general for aromatic hydrocarbons but is specific 

 for those of the benzene series. Hydrocarbons 

 with more than one benzene ring, like diphenyl, 

 ■ diphenylraethane, benzidine, naphthalene, anthra- 

 cene and heterocyclic compounds do not react. 

 The introduction into the ring of a COOH group, 

 NHNH, group or one or more phenol groups rend- 

 ers the hydrocarbon incapable of decomposing 

 hydrogen peroxide. The substitution of a nitro, 

 amino or aldehyde group, or of a halogen atom 

 for hydrogen does not prevent the breaking up of 

 hydrogen peroxide, although the catalytic power 

 of such substituted compound is much less than 

 that of the corresponding hydrocarbon. The de- 

 composition of hydrogen peroxide by aromatic 

 hydrocarbons and their derivatives is not caused 

 by changes in surface tension. 



Charles L. Parsons, 



Secretary 



SCIENCE 



A Weekly Journal devoted to the Advancement of 

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 ceedings of the American Association for 

 the Advancement of Science 



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