farkas_1934 =========== A\. Farkas, L\. Farkas and P\. Harteck, "Experiments on Heavy Hydrogen\. II\. The Ortho\-Para Conversion", Proc\. R\. Soc\. London A 144, 481 \(1934\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1098/rspa\.1934\.0062 `__ **Source kind:** measurement **Recorded technique:** Catalytic ortho\-para conversion of 'diplogen' \(D2, about 90 % D\) on active charcoal at 20\.4, 53 and 78 K, the ortho/para content measured by the thermal conductivity micro\-method of A\. Farkas \(two cells, resistance changes, Tables I\-II\); comparison with the concentrations calculated for Fermi\-Dirac and Bose\-Einstein statistics and nuclear spins 1/2 and 1 \(Table III\); the reconversion by oxygen at 293 K \(pp\. 482\-491\)\. **Materials in structured entries:** None recorded. **Dataset quantities:** None recorded. **Contents:** 0 datasets; 0 formulas. Curation notes -------------- A JSTOR reprint \(pdf page 1 is the JSTOR cover; pdf page 2 = p\. 481\: Proc\. R\. Soc\. Lond\. A 144, No\. 852, 29 March 1934, received 2 March 1934\); identity VALIDATED\_WITH\_WARNINGS; first page checked\. Page numbers are journal pages \(pdf page \+ 479\)\. What the paper states about the D2 spin statistics \(TC\-105\)\: the high\- temperature ortho\:para ratio is g\_ortho/g\_para = \(t \+ 1\)\(2t \+ 1\)/\(t\(2t \+ 1\)\) = \(t \+ 1\)/t, 'g is the nuclear statistical weight, being \(t \+ 1\)\(2t \+ 1\) for the ortho states, and t\(2t \+ 1\) for the para states' \(p\. 482\), t the nuclear spin; with Bose\-Einstein statistics 'all rotational states with even quantum numbers, are ortho states, and have the higher statistical weight' \(p\. 486\), 'in agreement with the statement of Lewis and Ashley' \(lewis\_1933\); 'Our ratios agree better with the spin t = 1' \(p\. 487\), and normal diplogen is 'n\-D2 = 2/3 o\-D2 \+ 1/3 p\-D2' \(p\. 488\)\. For t = 1 the printed weights are \(t \+ 1\)\(2t \+ 1\) = 6 \(even J\) and t\(2t \+ 1\) = 3 \(odd J\)\: this paper PRINTS the 6 \: 3 that raj\_2018 uses, which murphy\_1934 gives only as a ratio\. Caveat \(footnote, p\. 487\)\: 'the measurements cannot exclude definitely a nuclear spin of 1/2 as the relative changes in the concentrations \.\.\. are very similar to those for t = 1'; the spectroscopic ratio of murphy\_1934 \(1\.97 \+\- 0\.03 against 3 for spin 1/2\) settles it\. Summary \(pp\. 492\-493\)\: Bose\-Einstein statistics, 'the most probable value of the nuclear spin of diplogen is 1'; the deuteron magnetic moment 'about 1/5' of the proton's \(from the oxygen reconversion\)\. The measured quantities \(Table II\: resistance changes relative to normal D2 and their ratios 9\.2 \(cell I\) and 8\.8 \(cell II\) at 20\.4 K, 3\.4 at 53 K, 1 at 78 K; Table III\: the calculated ratios, Bose\-Einstein t = 1\: 9\.5, 3\.2, 1\) are conversion data, not refractive\: not extracted\. No refractive data\: no datasets\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- No datasets are recorded. Formulas -------- No formulas are recorded. 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.