356 



SCIENCE. 



[N. S. Vol. II. No. 38. 



CH2 



C-OH 

 C-CH3 

 CO 



Prof. A. B. Prescott, of Ann Arbor, gave 

 an account of work on periodides. A 

 classification and theoretical discussion of 

 the character of periodides was given and 

 was followed by a description of the follow- 

 ing periodides : 



A. Pyridine Alkyl periodide. 



1. Pyridine methyl pentaiodide. 



2. " " diiodide. 



3. " " triiodide. 



4. " " tetraiodide. 



5. " " octoiodide. 



6. " ethyl triiodide. 



B. Periodides of the amine and of the 

 tertiary ammonium base. 



1. Pyridine tetraiodide. 



2. " hydrogen pentaiodide (Da- 

 fert). 



C. Dipyridine trimethylene dibromide. 

 Whenever a mixture of alkyl iodide and 



iodine is added to pyridine, there will be 

 some formation of the periodide of the 

 amine base as well as of the pyridine alkyl 

 periodide. Mr. E. F. Flintermann and Mr. 

 B. F. Trowbridge have done most of the ex- 

 perimental work described. 



MONDAY MORNING, SEPTEMBER 2. 



Prof. C. L. Jackson, of Cambridge, read 

 a paper on ' Some New Color Keactions.' 

 On adding sodium ethylate to brom-di-nitro- 

 toluene and other similar bodies, unstable 

 compounds having brilliant colors were 

 formed. V. Meyer has made similar obser- 

 vations and the work will not be continued, 

 but results obtained indicate that the nitro 

 gi'Oup is directly aifected in the formation 

 of these bodies. 



Prof. Jackson read a second paper on 

 ' PicrylMalonic Ester.' Two forms melting 



at 58° and at 64° have been obtained. The 

 former was obtained at first, but repeated 

 attempts to prepare it a second time were 

 unsuccessful. 



A discussion on ' The Teaching of Organic 

 Preparations ' followed. Prof. P. C. Freer, 

 of Ann Ai'bor. introduced the subject. He 

 advocated the selection of some classical re- 

 search which is to be carefully studied and 

 the experimental work repeated by the stu- 

 dent. The discussion was continued by C. 

 L. Jackson, T. H. Norton, W. A. Noyes, A. 

 B. Prescott, W. H. Seaman and L. W. An- 

 drews. 



Prof A. B. Prescott gave an introduction 

 to the subject, ' Inherent Limitations in the 

 Accuracy of Analytical Work. ' An abstract 

 of a paper by A. A. Blair and J. E. Whit- 

 field on ' Ammonium Phosphomolybdate,' 

 and the reducing action of zinc in the re- 

 ductor, was given. Prof. E. D. Campbell 

 gave a provisional schedule of admissible 

 limits of accuracy in certain metallurgical 

 analyses. An abstract of a paper by F. P. 

 Dewey on ' Accuracy in Metallurgical Ana- 

 lysis ' was given by Prof. Prescott. In these 

 papers an attempt was made to make a be- 

 ginning toward the establishment of stand- 

 ards of accuracy which may be demanded 

 of chemists in various forms of analytical 

 work. The papers were discussed by W. 

 0. Atwater, L. F. Kebler, J. L. Howe, Wil- 

 liam McMurtrie and others. 



Prof T. H. Norton, of Cincinnati, illu- 

 strated the use of thioacetic acid as a labora- 

 tory reagent. Methods of preparation were 

 also discussed; in the discussion the odor of 

 the thioacetic acid was unfavorably noticed. 



MONDAY AFTERNOON, SEPTEMBER 2. 



Prof T. H. Norton spoke of the phospho- 

 rus contained in phospho-cereal. Of about 

 five per cent, of PoOj present, about one- 

 half passes into solution on boiling with 

 water for two hours. 



Prof. R. B. Warder, of Washington, rciid 



