644 



SCIENCE 



[N. S. Vol. LII. No. 1357 



quaternary addition products of suificiently pure 

 lepidine (or homologs of lepidine) give when 

 treated with alcoholic alkalis in hot, concentrated 

 solution, dyes of the isoeyanine type, similar to, 

 but not identical with, those given by the corre- 

 sponding derivatives of quinaldine. The prepa- 

 ration of 5 such dyes is described. The forma- 

 tion of isocyanines from lepidine confirms the 

 hypothesis, now generally accepted, that these 

 dyes contain two quinoline nuclei attached to a 

 oemtral carbon atom in positions 4 and 2, respec- 

 tively. 



KryptocyarUnes : A new series of photosensitiz- 

 ing dyes: Elliot Q. Adams and Herbert ,L. 

 Halleb. a new type of photosensitizing dye 

 having an absorption maximum near 7,000 A. and 

 a sensitization maximum near 7,400 A. is de- 

 scribed. These dyes are formed by the action of 

 alcoholic alkali and formaldehyde (or chloroform) 

 on the alkyl halides (or other quaternary addi- 

 tion compounds) of (sufBciently pure) lepidine 

 and its homologs. Dyes of the same or similar type 

 are produced under some circumstances in the 

 absence of formaldehyde or chloroform. Tenta- 

 tive suggestions are made as to the structure of 

 these dyes. The name "kryptocyanirie" is sug- 



Synthesis of photosensitizing dyes (,11.), dicya- 

 anine A.: L. A. Mikeska, H. L. Haller and E. 

 Q. Adams. Directions are given for the prepara- 

 tion of 2, 4-dimethyl-6-ethoxyquinoline from p- 

 phenetidine; for the preparation of the ethiodide 

 of this base, and, from it, the nitrate and iodide of 

 Dicyanine A. 



Naphthalene sulphonic acids. III. An alterna- 

 tive method for the qualitative detection of naph- 

 thalene S-7 and 1-6 disulphonio adds. J. A. 

 Ambler. In naphthalene sulphonic acids. II. A 

 method for the qualitative determination of some 

 of the naphthalene sulphonic acids, by J. A. 

 Ambler and E. T. Wherry, read at the meeting of 

 the American Chemical Society at St. Louis in 

 April a method of detecting naphthalene 1-6 and 

 2-7 disulphonic acids by a microscopic examina- 

 tion of their |3-naphthylamine salts, was given. It 

 is also possible to detect these two acids in mix- 

 tures by the different solubility of their /3-naph- 

 thylamine salts in 4 volumes of 95 per cent, alco- 

 hol and 1 volume of water, the 2-7 salt being more 

 ■insoluble. The 1-6 acid is detected by converting 

 to the sodium salts and subsequent treatment with 

 sulphuric acid, in which the sodium salt of the 

 1-6 acid is more insoluble. 



, An investigation of the N. S. Passay of phos- 

 phoric add and soluble phosphates: A. B. Steabn, 

 H. v. Faek and N. P. Knowlton. The N. S. P. 

 method is incapable of yielding true results except 

 at one specific concentration, namely, 6.2 mg. per 

 c.c. of P2O5 in sol. The error varies from about 

 + 3 per cent, at a concentration of .62 mg. per c.c. 

 to — 8 per cent, at a cone, of 10.9 mg. per c.c. 

 This is probably due to the formation of acid phos- 

 phates of silver which are slightly soluble, the 

 amount formed increasing rapidly as the phos- 

 phate concentration is increased and the excess of 

 silver nitrate is simultaneously decreased. By 

 modifying the method to the extent of transform- 

 ing the acid to the tri-sodium salt results are ob- 

 tained which coincide with the results yielded by 

 the pyrophosphate method and are independent of 

 the concentration. 



The production of American storax from the 

 red gum tree: S. A. Mahood. 



Detection of some substituted sulphonic adds: 

 D. F. J. Lynch. In the work on substituted sul- 

 phonic acids in this laboratory, the need of some 

 quick method of detection and identification for 

 such acids as 1-8 dinitro naphthalene 3-6 disul- 

 phonic acid, 1-8 diamino naphthalene 3-6 disul- 

 phonic acid, l-amiuo 8 naphthol 3-6 disulphonic 

 acid (H acid), and 1-8 dihydroxy naphthalene 3-6 

 disulphonic acid (chromotrope) was felt. Mix- 

 tures of these acids were encountered in our work 

 on the nitration of 2-7 naphthalene disulphonic 

 acid and the subsequent reduction and hydrolysis 

 of the nitro compound formed. Each of these 

 four acids can be identified in the presence of the 

 other three by the formation of salts with organic 

 bases. 



Benzene disulphonic acid from benzene mono- 

 sulplionic acid: C. E. Senseman. Barium benzene 

 monosulphonate is treated with concentrated sul- 

 phuric acid at temperatures of 220°, 250° and 

 280°. The quantities of acid used range from 50 

 per cent, excess to 700 per cent, excess. The 

 duration of the various experiments is from 8 to 

 10 hours. The progress of the reaction is deter- 

 mined in each case by removing a sample at the 

 end of each hour and analyzing for the disul- 

 phonic acid. Vanadium pentoxide and sodium sul- 

 phate are tried out as catalysts. In some cases an 

 increased yield of 20 per cent, results. 



Qualifications of organic chemists: M. L. Cross- 

 ley. Uniformity of action by men who employ 

 chemists in passing upon their qualifications is 



