cuthbertson_1914 ================ C\. Cuthbertson and M\. Cuthbertson, Phil\. Trans\. R\. Soc\. A 213, 1 \(1914\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1098/rsta\.1914\.0001 `__ **Source kind:** measurement **Recorded technique:** Jamin\-type interferometer with a refractometer tube \(about 1 m\)\: bands counted as the gas is admitted to atmospheric pressure, green mercury line \(5461\) for the absolute refractivity; the dispersion at seven other visible lines \(6708 Li, 6438 Cd, 5790 and 5770 Hg, 5209, 5085 and 4800 Cd\) measured relative to it with a compensator \(bands read to 1/15\)\. Ozone made by silent discharge in pure dry oxygen \(5\-7 % by volume, once 10 %\), its content found by destroying it with heat and measuring the volume increase \(first method\) or by KI titration \(second method\)\. N2O from fractionated commercial gas and from ammonium nitrite on hydroxylamine sulphate\. **Materials in structured entries:** N2O, O2, O3 **Dataset quantities:** refractivity **Contents:** 10 datasets; 2 formulas. Curation notes -------------- The paper's title in the library carries a junk prefix \('info getting lost \.\.\.'\); the paper is 'I\. On the Refraction and Dispersion of the Halogens, Halogen Acids, Ozone, Steam, Oxides of Nitrogen and Ammonia', received 18 October 1912, published separately 4 April 1913 \(Phil\. Trans\. A 213, 1\-26, 1914\)\. Only ozone, oxygen and nitrous oxide are curated species; the halogens, halogen acids, steam, ammonia and nitric oxide are skipped\. Standard state \('theoretical density', pp\. 5\-6\)\: all refractivities are reduced 'to the values which they would have had if the gas or vapour had the density of hydrogen at 0 C and 76 cm \(0\.000089849 g/cm^3\) multiplied by the ratio of the theoretical molecular weight of the substance in question to that of hydrogen', written \(mu \- 1\) D/\(d0 76\)\. That is a fixed molar density, the real molar volume of hydrogen at 0 C and 76 cm, which the paper takes as 22428\.8 cm^3 \(p\. 6\)\. It is recorded as the ideal\-gas state with that molar volume\: 273\.15 K and p = R T / V = 8\.314462618 x 273\.15 / 22428\.8e\-6 = 101258\.0 Pa, density = ideal \(the number density is then exactly N\_A / 22428\.8 cm^3, 0\.066 % below the ideal gas at 0 C and 1 atm\)\. For chlorine the reduction multiplied by the ratio of molar volumes \(pp\. 5\-6\); for N2O the thermal expansion coefficient used was 0\.00371 \(p\. 24\)\. Wavelengths are air wavelengths in angstroms as used in 1912 \(the green line printed 5461 or 5460\.7\), recorded as standard air\. Accuracy \(p\. 25\)\: refractivities for the green line 'generally agreed to 1 part in 500, and the mean is probably within 1 in a 1000 of the truth\. In iodine and ozone, however, the errors may amount to 1 or 2 per cent\.' Dispersion \(relative to the green line\)\: 'the error should not exceed 1/200 of the effect itself' \(p\. 25\)\. Ozone\. The O3 refractivity at the green line comes from O2\-O3 mixtures of 3\.5\-9\.5 % ozone, with the oxygen value 0\.0002717 of the authors' 1909 paper, so every error is multiplied by about 100/x\: Tables IX \(first method, mean 525\) and X \(second method, mean 516\.5\); the authors adopt mu = 1\.00052, 'unsafe to rely on this number beyond the second significant figure' \(p\. 19\)\. The O3 dispersion \(Table XI, last row\) is derived\: the ozone fraction of the mean mixture \(6\.1764 %\) is fixed by assuming \(mu\_5461 \- 1\) = 0\.000520 for ozone, and the O2 row, reproduced from the 1909 paper, is subtracted \(p\. 20\)\. Only the shape is independent \(the 5461 value is 52000 by construction\), and the errors of the mixture and of the O2 values are amplified 16 and 15 times; the mixture dispersion \(544 x 1e\-8 between 6708 and 4800\) known to 1/200 gives about 44 x 1e\-8 on each O3 value\. Recomputing the O3 row from the printed means and O2 row reproduces it within 10 x 1e\-8 \(the means are rounded; checked 2026\-09\-24\)\. The mixture rows are not extracted \(mixtures are not species\)\. Nitrous oxide\. Seven absolute determinations at the green line \(three series, mean 5096 x 1e\-7\); 'as traces of air were probably present we think 5100 a more trustworthy value than the exact experimental mean, and probably correct to 1/500 at least' \(p\. 24\)\. Table XIV \(whose caption lacks the gas\) gives the dispersion relative to that value \(51000 at 5460\.7\)\. Mascart's values reproduced on p\. 23 \(tbl\_2cea631c5dc8, 'n' itself, gas with 10 % impurity\) are not extracted\: the vocabulary has no refractive\-index quantity and n \- 1 would have to be computed from the printed n; they are also unreliable by the paper's account\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- cuthbertson\_1914/ozone\_dispersion ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ozone_dispersion", "material": "O3", "file": "O3/cuthbertson_1914__ozone_dispersion.csv", "table": "tbl_4bf7db766c5d", "quantity": "refractivity", "scale": 1e-08, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "primary", "uncertainty": { "absolute": 44, "level": "bound", "systematic_relative": 0.0115 } } Table XI 'Refractivities of O3'\: derived from mixture means minus the reproduced 1909 O2 values, with the ozone fraction fixed by assuming 520e\-6 at 5461\. The shape is the information; the scale is the adopted 520 \(1\-2 %, a bound\: systematic\_relative 0\.0115 as a uniform half\-width of 2 %\)\. Per point about 44 x 1e\-8 \(the 1/200 dispersion error amplified by 100/6\.18; a bound\)\. cuthbertson\_1914/ozone\_adopted ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ozone_adopted", "material": "O3", "table": "text", "quantity": "refractivity", "scale": 1e-06, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "check", "uncertainty": { "relative": 0.02, "level": "bound" } } 1 inline points in the source record. p\. 19\: 'the refractive index of pure ozone for the mercury green line is mu = 1\.00052' \(the mean 520\.7 of the two methods, to two significant figures\); errors 'may amount to 1 or 2 per cent' \(p\. 25\)\. The same number anchors ozone\_dispersion at 5461, so it is a check, not a second datum\. cuthbertson\_1914/ozone\_method1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ozone_method1", "material": "O3", "file": "O3/cuthbertson_1914__ozone_method1.csv", "table": "tbl_6f597b2ac7a8", "quantity": "refractivity", "scale": 1e-06, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "check" } Table IX \(first method, ozone by thermal decomposition\), experiments 1\-6, 8, 9; mean of all nine 525\. The individual values scatter by \+\-4 %; they are averaged into the adopted 520\. cuthbertson\_1914/ozone\_method1\_bracketed ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ozone_method1_bracketed", "material": "O3", "file": "O3/cuthbertson_1914__ozone_method1_bracketed.csv", "table": "tbl_6f597b2ac7a8", "quantity": "refractivity", "scale": 1e-06, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "excluded" } Table IX experiment 7, printed in brackets\: 'Not reliable, percentage of ozone too small' \(3\.5 %\)\. cuthbertson\_1914/ozone\_method2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ozone_method2", "material": "O3", "file": "O3/cuthbertson_1914__ozone_method2.csv", "table": "tbl_f49a5176a7d2", "quantity": "refractivity", "scale": 1e-06, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "check" } Table X \(second method, ozone by titration, 'more concordant'\), experiments 1, 2, 4\-6; mean of all six 516\.5\. cuthbertson\_1914/ozone\_method2\_bracketed ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ozone_method2_bracketed", "material": "O3", "file": "O3/cuthbertson_1914__ozone_method2_bracketed.csv", "table": "tbl_f49a5176a7d2", "quantity": "refractivity", "scale": 1e-06, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "excluded" } Table X experiment 3, printed in brackets\: 'Not very trustworthy'; 'the results \.\.\. would be even better if the third experiment were omitted' \(p\. 19\)\. cuthbertson\_1914/oxygen\_1909 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "oxygen_1909", "material": "O2", "file": "O2/cuthbertson_1914__oxygen_1909.csv", "table": "tbl_4bf7db766c5d", "quantity": "refractivity", "scale": 1e-08, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "unknown", "use": "reproduced", "reproduced_from": [ "C. Cuthbertson and M. Cuthbertson, Proc. R. Soc. A 83, 151 (1909)" ] } Table XI 'Refractivities of O2', 'taken from our previous determinations' \(p\. 20\); 27170 at 5461 is the 0\.0002717 quoted on p\. 17\. The 1909 paper's own reduction \(possibly plain 0 C and 760 mm\) is not stated here\. cuthbertson\_1914/n2o\_green\_line ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "n2o_green_line", "material": "N2O", "file": "N2O/cuthbertson_1914__green_line.csv", "table": "tbl_6f5db40b38bd", "quantity": "refractivity", "scale": 1e-07, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "check" } The seven absolute determinations \(p\. 24; cells split as in the image\), mean 5096; the authors adopt 5100 \(suspected traces of air\), which anchors n2o\_dispersion\. cuthbertson\_1914/n2o\_dispersion ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "n2o_dispersion", "material": "N2O", "file": "N2O/cuthbertson_1914__dispersion.csv", "table": "tbl_d05d1c4d670a", "quantity": "refractivity", "scale": 1e-08, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "primary", "uncertainty": { "absolute": 4.4, "level": "bound", "systematic_relative": 0.0012 } } Table XIV 'Observed' \(N2O\)\: relative to the adopted 5100e\-7 at the green line \('correct to 1/500 at least', a bound\: systematic\_relative 0\.0012 as a uniform half\-width\)\. Per point\: 'the error should not exceed 1/200 of the effect' \(871 x 1e\-8 across the range, so 4\.4\)\. cuthbertson\_1914/n2o\_dispersion\_calculated ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "n2o_dispersion_calculated", "material": "N2O", "file": "N2O/cuthbertson_1914__dispersion_calculated.csv", "table": "tbl_d05d1c4d670a", "quantity": "refractivity", "scale": 1e-08, "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "use": "check" } Table XIV 'Calculated'\: the one\-term Sellmeier formula \(p\. 25\)\. Formulas -------- cuthbertson\_1914/ozone\_two\_point ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ozone_two_point", "material": "O3", "equation": "p. 20 (text)", "printed": "mu - 1 = 2.0414 x 10^27 / (4221.3 x 10^27 - n^2)", "variable": "n: frequency, 3 x 10^10 / lambda(cm), lambda in air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "range": "6708-4800 A (through the two end points only)", "coefficients": { "N": "2.0414e27", "n02": "4221.3e27" }, "check": "Gives 52083 x 1e-8 at 5461 (the paper: 52082, against the derived 52000) and 50765 and 53291 at 6708 and 4800, the two points it was drawn through (checked 2026-09-24)." } Fixed from mu\_6708 \- 1 and mu\_4800 \- 1 alone; the authors infer that 'a second term is required' because the measured curvature is larger\. cuthbertson\_1914/n2o ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "n2o", "material": "N2O", "equation": "p. 25 (text)", "printed": "(mu - 1) D/(d0 76) = 5.6685 x 10^27 / (11416 x 10^27 - n^2)", "variable": "n: frequency, 3 x 10^10 / lambda(cm), lambda in air", "state": { "pressure_pa": 101258.0, "temperature_k": 273.15 }, "density": "ideal", "range": "6708-4800 A", "coefficients": { "N": "5.6685e27", "n02": "11416e27" }, "check": "Reproduces Table XIV's calculated column within 1.6 x 1e-8 at six wavelengths, 2.2 at 5209.1 and 6.7 at 4799.9 (51413.3 against 51420): the printed constants are rounded (checked 2026-09-24)." } One\-term Sellmeier fitted by the paper's modified least squares \(p\. 26\)\. Corrections ----------- No dataset errata are recorded in this source record. Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register ` for the checks and decisions.