456 



SCIENCE 



[Vol. LVI, No. 14.51 



one of the several on the naphthol ring replaced 

 by a diazo group, since the napMhol-sulfonic 

 acids having a sulfonic acid group in position 8 

 do not form nitroso compounds, and since the sub- 

 stitution of an aryl radical for hydrogen of the 

 hydrosyl group diminishes the reactivity of the 

 adjacent hydrogen atom, as is evidenced by the 

 fact that coupUng no longer takes place on the 

 naphthol ring, it is suggested that there is a 

 dynamic relationship between the hydroxyl rad- 

 ical and the adjacent hydrogen atom, that this 

 relationship is enhanced by a sulfonic acid group 

 in position 3 and inliibited by a sulfonic acid 

 group in position 8. It is further suggested that 

 this condition of a "loose" hydrogen atom when 

 position 8 is not occupied constitutes a condition 

 of an "open field of reactivity," while the con- 

 dition of the hydrogen atom when position 8 is 

 occupied constitutes a condition of a "closed 

 field of reactivity." An open field of reactivity 

 is considered necessary for the formation of pre- 

 liminary addition products, before any can result 

 in the formation of stable reaction products. 



Rhyilimio lands of dyes on fdier paper iy 

 evaporation. The refractivity, surface tension, 

 conduotivity, viscosity and Broimian movement 

 of dye solutions: Eakl C. H. Davies. (Lantern. 

 Illustrated). Striking bands of dyes have been 

 obtained, bv a method of evaporation, in filter 

 paper and with unglazed porcelain. There are no 

 marked relations between the formation of these 

 bands and the physical properties of the dye solu- 

 tions, but it is probable that the viscosity of the 

 very concentrated solutions is important. Oriented 

 adsorption takes place in rhythmic band forma- 

 tion. A study was made of 62 dyes with 3 varie- 

 ties of filter paper. 



Adsorption phenomena in the application of 

 dyes to plain and mordanted fairies: L. W. 

 Parsons and E. D. Lord. This paper deals with 

 adsorption phenomena which occur in the dyeing 

 of wool and mordanted cotton. The results are 

 treated by the Freoidlich adsorption equation, 



_i __ fcc -, where — is the grams of dye adsorbed 

 m n m 



per gram of adsorbent, c is the concentration of 

 dye in the bath in equUibriuni with the dyed 



fibres, and Jc and - are constants for each indi- 



n 

 vidual dye. Characteristic samples of pure dyes 

 containing various ehromophore groupings were 

 studied, the data applied to the adsorption equa- 



1 

 tion and the factors affecting the exponent, -, are 



discussed. (1) In azo dyes the value of - is in 



general high, and only slightly affected by the 

 addition or removal of OH or SosNa groups. 



(2) Thiazene dyes have particularly a low value. 



(3) Xanthene dyes containing the grouping 

 COON or COOCH3 have a low value for the ex- 

 ponent, the value being raised, however, if this 

 group is absent. (4) The nitro group raised the 



1 

 value of - provided that there is not a counter- 

 n 



acting factor. (5) Triphenylmethane dyes have, 



in general, a low value. (6) In the case of mor- 



1 ... 



danted cotton - is particularly low, indicating 

 n 



that adsorption is a major factor. (7) This 

 work is still in its infancy, but it is believed that 

 a systematic study of such data and an applica- 

 tion of it to the dyeing processes will lead to 

 generalities of interest both to the practical dyer 

 and to the physical chemist. 



Dyes of the dinitro-malachite green series: 

 T. B. Downey with Alexander Lowt. 2, 4-dini- 

 trobenzaldehyde was condensed with dimethyl- 

 aniline, benzyl-ethj'l-aniline and diethyl-aniline (in 

 the proportion of 1 mol to 2 mols.), yielding 

 2, 4-dinitro-malachite-green dyestuffs which have 

 the characteristic blue-green color typical of the 

 malachite green series. The properties of the 

 leucobases and dyes derived therefrom were 

 studied. Samples of the dyes and dyeings will 

 be shown. 



Catalytic oxidation of anthracene to anthra- 

 quinone: 0. E. Senseman and 0. A. Nelson. 

 The importance of anthraquinone as an interme- 

 diate in the manufacture of dyes is shown. Men- 

 tion is made of the old methods of manufacture, 

 chief among which is the chromic acid method. 

 The catalytic method, patented by Gibbs and 

 Conover, and worked out by the authors, is de- 

 scribed in detail. The apparatus consists essen- 

 tially of: (1) a carburetor, (2) reaction chamber 

 and (3) sublimer for collecting the reaction 

 products. All these parts are made of glass and 

 heated by well-insulated electric heaters. The 

 carburetor is built with two air inlets, one ar- 

 ranged so as to sweep over the molten anthracene 

 and thus carry a definite amount of the hydro- 

 carbon into the reaction chamber, the other ar- 

 ranged so as not to interfere with the work of 

 the first but -to vary the air-anthracene concentra- 

 tion as desired. Four methods of supporting the 

 catalyst, vanadium pentoxide, are described. 

 They are: (1) by boats, (2) by discs, (3) by 



