October 20, 1922] 



SCIENCE 



457 



pumice, (4) by fusing to a glass tube. The sub- 

 limer, as used during most of the runs, consists 

 of a Kjeldahl ilask with neck removed, and joined 

 to the reaction chamber by a ground-glass joint. 

 Tables were compiled showing the influence of 

 different variables in the production of anthra- 

 quinone. The maximum yield obtained was 85.3 

 per cent, of the theoretical. 



Equations for vapor pressures and latent heat 

 of vaporization of naphthalene, anthracene, 

 phanenthrene and anthraquinone : O. A. Nelson 

 and C. E. Senseman. This work deals only with 

 the calculated vapor pressures and latent heats of 

 vaporization of naphthalene, anthracene, phenan- 

 threne and anthraquinone, and is an outgrowth 

 of the work published by the authors on the ob- 

 served vapor pressures of these compounds in 

 ■7. Ind. Eng. Chem., 14 (1922), 58. The calcula- 

 tions were made by applying the Clapeyron equa- 

 tion of state. A discussion of the derivation of 

 the equation is given. The entropy of vaporiza- 

 tion of the same compounds was also calculated 

 and the conclusion arrived at that all form 

 normal liquids. Tables for observed and calcu- 

 lated vapor pressures were given for each com- 

 pound. In each case the calculated agrees favor- 

 ably with the observed. 



Cariazole, its purification and vapor pressure 

 determination: C. E. Senseman and O. A. Nel- 

 son. Carbazole of 82 per cent, purity was washed 

 three times with benzene at a temperature of 50° 

 G. Successive crystallizations from benzene and 

 toluene followed, giving a product melting at 

 244.8° C. Analysis showed the presence of 8.22 

 per cent, of nitrogen, while the theoretical per , 

 cent, present is 8.38. Using this material vapor 

 pressure determinations were made by the method 

 and apparatus described previously by the 

 authors in J. Ind. Eng. Chem., 14 (1922), 58. 

 Two tables were given. Table I records the pres- 

 sures and corresponding temperatures. Table II 

 gives the pressures at 5° temperature intervals 

 read from a curve made from the observed read- 

 ings. The boiling point was found to be 354.76° 

 C. This constant was previously reported in the 

 literature to be 351.5° C. Erom the Clapeyron 

 equation of state a formula was derived for cal- 

 culating the vapor pressures at the various tem- 

 peratures. These calculated pressures closely ap- 

 proximate the observed ones. 



The influence of change in concentration on the 

 absorption spectra of dyes: W. C. Holmes. A 

 brief review of the literature on the subject is 

 given. An outline of the preliminary results ob- 

 tained by varying the concentration of a large 



number of dyes over a wide range is presented, 

 together with representative absorption curves 

 illustrating various types of behavior. The inter- 

 pretation of results and their bearing upon the 

 condition of dyes in solution is discussed. 



The synthesis of di-cyanine A: S. Palkin. In 

 the synthesis of dieyanine by the action of sodium 

 ethylate on an alpha, gamma quinoline interme- 

 diate it was found that the relative proportion of 

 dieyanine and cyanine produced varied consider- 

 ably with the same sample of intermediate, in dif- 

 ferent experiments. The possible presence of 

 other intermediates was not thought to be wholly 

 responsible for the formation of contaminating 

 dyes. A study of the influencing factors resulted 

 in the development of an improved process for 

 this dye, which depends upon the action of sodium 

 sulfide and chloroform on an alpha, gamma quino- 

 line intermediate in alcoholic solution. At least 

 tv/o other types of dyes are formed simultaneously 

 by this method, one showing an absorption spec- 

 trum maximum at 6200 A (kryptocyanine). Op- 

 timum conditions liave been worked out for the 

 preparation of dieyanine A IV (absorption maxi- 

 mum about 6720 A). The resulting product was 

 found to have sensitizing power equal to Hoechst 

 Dieyanine. The yield of dye by this method ia 

 over txieWe times that obtainable by any previous 

 method. 



The preparation and separation of the ortho- 

 and nara-chloro-anilines : H. C. Bashioum and 

 P. O. PowEES. The work was done to find a meth- 

 od capable of technical development for the 

 preparation of the intermediates. Chloro-benzene 

 was nitrated, and the mixture of o- and p-nitro- 

 chloro-benzene was cooled, separating a part of 

 the para isomer. The remaining mixture of nitro 

 compounds was heated to distill off any remaining 

 chloro-benzene and then reduced by boiling with 

 iron and dilute hydrochloric acid. Steam distilla- 

 tion was used to remove the ortho-chloro-aniline 

 which was obtained very nearly pure. Para 

 chlor-o-aniline can be obtained by neutralizing and 

 continuing the distillation with steam. Several 

 other methods of separation were investigated. 



The preparation of phenyl-thioglycol-o-oar- 

 hoxylic acid, thioindoxyl-carTjoxylio acid, thio- 

 indoxyl and tMoindigo: M. X. Sullivan. The 

 brick-red precipitate obtained by running HgS 

 into diazotized anthranilio acid at 0°-5° C. was 

 treated with chloro-acetic acid in slightly alkaline 

 medium and warmed to 75° C. The filtrate there- 

 from cooled and acidified with HCl gives phenyl- 

 thio-glycol-o-carboxylic acid. This heated with 

 5 parts NaOH and a little water gradually to 



