220 



SCIENCE 



[N. S. Vol. XXXIV. No. 



or supplemented by tannic acid. The gallic acid, 

 furthermore, was not as efficient as the tannic acid 

 in stimulating the formation of the enzyme. 



Some work has been done showing that the 

 quantity of a particular enzyme produced irre- 

 spective of the character of the carbon nutrient, 

 can be increased in amount by offering the organ- 

 ism the carbon compound which is transformed 

 by the enzyme in question. No work apparently 

 has been reported on the effect of concentration 

 of the transformable substance on the quantity of 

 the corresponding enzyme produced. Employing 

 the two organisms mentioned, the writer made 

 experiments, in which a modified Czapek's solu- 

 tion was the nutrient medium — in this the concen- 

 tration of sugar was made 10 per cent., and it 

 was supplemented by tannic acid in concentrations 

 varying from 0.01 per cent, to 10 per cent. The 

 quantity of the enzyme produced was augmented 

 by increase in concentration of the tannic acid. 

 None, however, was formed when the concentration 

 of tannic acid was as low as 0.01 per cent. 



Similar results were obtained with Penicillium 

 sp. Aspergillus candidus, Aspergillus ory^ce and 

 Penicillium granulatum cultivated in a synthetic 

 solution in which the carbon was supplied as 5 

 per cent, cane sugar and supplemented by 2 per 

 cent, tannic acid also developed the enzyme tan- 

 nase. Penicillium expansum in a similar solution 

 did not develop the enzyme. 



The enzyme tannase would fall then in the third 

 class, as described by Went, which class includes 

 only those enzymes which are produced when a 

 particular carbon compound is present in the 

 nutrient solution. 



The Synthesis of Fats by the Action of Emymes: 



F. L. DuNLAp and L. O. Gilbert. 



Five grams oil-free castor bean, 5 g. flaxseed, 

 25.5 g. glycerol, 16.7 g. Kahlbaum's oleic acid 

 were triturated in a mortar till emulsified. The 

 flaxseed was introduced to perfect the emulsion. 

 It is without action.' This emulsion was allowed 

 to stand and its acidity titrated at intervals. 

 After eleven days the loss of acidity was such as 

 to correspond to a disappearance of over 26 per 

 cent, of the total oleic acid present, so that the 

 enzyme of ricinus has undoubted synthetic power. 



On the Measurement of the Oxidase Content of 



Plant Juices: H. H. Bunzel. 

 The Pigmentation of the Adult Periodical Cicada, 



with a Note on Chemical Anti-oxidases : Eoss 



Aiken Goetner, the Carnegie Institution of 



Washington. 



The black pigment of the periodical cicada 

 {Tihicen septendecim L.) is shown to be produced 

 by the interaction of a chromogen and an oxidase 

 of the tyrosinase group. Coloration proceeds after 

 death but does not produce the normal uniform 

 coloration, since, apparently, the tyrosinase is se- 

 creted together with the new cuticula, and after 

 death this secretion ceases. 



In the note on chemical anti-oxidases the sug- 

 gestion is made that, perhaps, dominant whites are 

 due to the presence of aromatic compounds carry- 

 ing two hydroxyl groups in meta position to each 

 other. It was noted that tyrosin did not produce 

 the typical coloration in the presence of tyrosinase 

 when orcin, resorcin or phloroglucin — all meta-di- 

 hydroxyl benzol derivatives — were present in the 

 solution. This result was, apparently, caused by 

 the tyrosinase being affected in the same manner 

 as though an anti-oxidase were present, for proof 

 was given that the tyrosin had not united chem- 

 ically with the m-di-hydroxyl compound, and data 

 were also given which makes it appear very im- 

 probable that the cause lies in a more rapid 

 oxidation of the orcin, etc., to colorless derivatives. 

 The only other alternative is that the action is 

 of the same nature as that of a true anti-oxidase. 

 If, therefore, through some body process, an addi- 

 tional hydroxyl were added to tyrosin adjacent to 

 the alkyl chain, a compound would result which 

 should not give colors with tyrosinase, nor allow 

 colors to be produced even though tyrosin were 

 present. Such a situation would produce dom- 

 inant whites. 



A Study of the Methan Fermeniation in the First 



Stomach of Buminants: Sleetee Bull. 



Crude fiber, or cellulose and starch, undergo a 

 fermentation in the paunch of ruminants with the 

 formation of methane carbon dioxide, acetic acid, 

 butyric acid and isobutyric acid. 



By the artificial fermentation of cellulose it was 

 found that 1.0 gm. of cellulose produced .033- 

 .040 gm. of methane. 



Omeliansky found that one gram of cellulose 

 produced .068 gm. of methane, .3057 gm. of acetic 

 acid and .2038 gm. of butyric and isobutyric acid. 



Knowing the energy value of the cellulose — 

 4.220 cals. — and that of the products of the fer- 

 mentation, it may be computed that 1.4048 cals. 

 of energy are liberated as ' ' heat of fermenta- 

 tion" in the fermentation of one gram of cellu- 

 lose. Expressed in terms of methane, 1.1549 cals. 

 of energy are lost as ' ' heat of fermentation, ' ' for 

 every calory of methane excreted by the animal. 



