Chart presentation of recent work on indicators / by George Stanley Walpole ; [communicated by H.H. Dale].

  • Walpole, George Stanley.
Date:
[1910?]
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: Chart presentation of recent work on indicators / by George Stanley Walpole ; [communicated by H.H. Dale]. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    ON CHART PRESENTATION ON RECENT WORK INDICATORS By GEOEGE STANLEY WALPOLE, B.Sc., A.I^/ FT.-, From the Wellcome Physiological ResearcF^'Laboratories, , Herne Hill, S.E. Commxinicated by Dr. H. H. Dale (Received June 18th, 1910) During recent years the change of mental attitude of scientific workers towards indicators has been very pronounced. The advent of the hydrogen electrode, and the results obtained by its use in the hands of ;• FriedenthaP and Salni,’^ have resulted in the addition of data founded on f a quantitative basis to the empirical rules of ten years ago. In a recent j paper, S. P. L. Sorensen^ has published the results of an investigation of * the hydrogen ion concentration of various mixtures of pure substances J| and the corresponding colour changes of an exhaustive list of indicators. ‘ Reaction ’ and ‘ Hydrogen ion Concentration ’ £ It will he necessary in the ensuing description to affix, for the time * being at any rate, explicit meanings to some terms frequently employed. ^ By means of hydrogen electrodes it is possible to determine directly the liydrogen ion concentration of a solution (expressed, of course, in terms , of the normal hydrogen solution, one gram per litre). The value for any sohition is conveniently expressed as a power of ten (that is to say, the ^ common logarithm), and indicated by the symbol p+, the negative sign t being understood. Eor instance, centinormal hydrochloric acid is T 0 00916 N with respect to its hydrogen ions, and the hydrogen ion I . H. Friedontlial, Zeilschr. j. Electroche.mie, Fol. X. p. 113. 1904. 2. Ed. Saltn. ibid.. Vol. X, p. 341, 1904; Ed. Salm and H. Friedenthal, ibid., \'oI. - Xlll, p. 126, 1907, &c. . 3. S. P. L. Sorenson, Comptss Itendus dea Travaiix dii Laboralotre. de Carlsberg, Copenhagen, Vol. VIII, pp. 1-168, 1909 ; I'i)!. VIII. pp. 390-401, 1909.