Queenwood College | Stockbridge | Hants | Oct[o]b[e]r 30th 60.
My dear John,
I suppose my last letter1 came to your hands on Wednesday last.
There appear to be, without doubt, two bodies of similar properties, which are called by the same name—ozone.2 If the fact is true, that perfectly pure oxygen can by means of electric sparks be converted into what is called ozone, and if it is true, that the oxygen obtained from water by passing a electric current through the same, contains a body of the composition HO3 and comporting itself like the electrified oxygene, then it follows that we have
a) modified oxygene
b) a peroxide of hydrogen
both in properties very much alike and going by the same name.
About Baumerts and Bunsens experiments3 I have no doubt and scarcely any with regard to the electrified oxygen. De la Rive4 and Marignac,5 Becquerel6 and Fremy,7 Berzelius,8 Marchand9 &c &c all profess to have experimented with dry oxygen;
Have you not examined perfectly pure and dry oxygen enclosed in a glass tube and treated with electric sparks? If the presence of nitrogen is no objection, then the best mode of obtaining ozone would be by leaving a piece of phosphorous in moist and confined air. If the presence of nitrogen is objected to then pass pure oxygen over phosphorous, 2/3 of which is immersed in water, at a temperature of 36oC. Part of the oxygen is converted into ozone and it is only necessary to pass the ozonised oxygen over anhydrous chloride of calcium or better phosphoric acid in order to obtain it dry.
According to my knowledge the best way to reduce ozone to the common oxygen is, to pass the said ozone through a red hot tube; also the powder of charcoal, if shaken with ozone, converts the latter in common oxygen, or oxygen and water, perhaps a small quantity of carbonic acid is formed; at all events all the ozone is destroyed.
We can determine 1/50,000 part of ammonium and I dare say less than 1/100 000 part of chlorine or any other gas of decided chemical properties, in our atmosphere; of course such numbers depend entirely on the nature of the gas.
I am happy to hear you are so strong in body and mind and so successful in your investigation. You may depend, I shall not divulge or mention the subject of your labours to any one.10
Always yours | H. Debus
RI MS JT/1/D/26
my last letter: letter 1732. This letter is a reply to letter 1733.
ozone: the chemical nature of ozone was not clear at the time. Ozone was considered either to be a form of oxygen or a compound with hydrogen. Though Tyndall thought at the time from his absorption of heat experiments that oxygen was atomic, not molecular, he correctly deduced that ozone was a form of oxygen. We now know that oxygen molecules contain two atoms, O2, and ozone molecules three, O3.
Baumerts and Bunsens experiments: Friedrich Moritz Baumert (1818–65), see M. Baumert, ‘Ueber eine neue Oxydationsstufe des Wasserstoffs und Ihr verhältnis zu Ozon’, Poggend. Annal., 89 (1853), pp. 38–55; ‘Zur Ozonfrage’, Poggend. Annal., 99 (1856), pp. 88–94; ‘Ueber das elektrolytisch entwickelte Ozon’, Ann. Chem. 101 (1857), pp. 88–90. Robert Bunsen (1811–99), see R. Bunsen, Gasometrische Methoden (Braunschweig: Friedrich Vieweg und Sohn, 1857). Specific publications by Bunsen on ozone have not been identified, but his key work in developing techniques to separate, measure, and identify chemical compounds was picked up on by others and resulted in new findings on ozone. See, for example, M. Soret, ‘XXIX. Experiments on Ozone. In a Letter to Professor Tyndall’, Phil. Mag., 25 (1863), pp. 208–10. In this letter, Soret describes how he used one of Bunsen’s methods of gas analysis, as well as Baumert’s experiment using electrified oxygen in his investigations on ozone.
De la Rive: Auguste-Arthur de la Rive. He published on his work with Marignac in the postscript of: A. de la Rive, ‘Sur les mouvements vibratoires que déterminent dans les corps, soit la transmission des courants électriques, soit leur influence extérieure’, C. R. Hebd. Seances Acad. Sci., Ser. C, 20 (1845), pp. 1287–91.
Marignac: Jean Charles Marignac (1817–94). J. C. Marignac, ‘Sur la nature et la production de l’ozone’, Archives de électricités. (Supp. a la Bibliothéque Universelle de Genève), 5 (1845), pp. 5–11. A similar paper in Comptes Rendus omitted the part about the dry oxygen.
Becquerel: Alexandre Edmond Becquerel (1820–91). E. Fremy and E. Becquerel, ‘Recherches électrochimiques sur les proprietés des corps électrisés’, Annal. Chim. et Phys., 3rd series, 35 (1852), pp. 62–105.
Fremy: Edmond Frémy (1814–94). See n. 6.
Berzelius: Jöns Jacob Berzelius (1779–1848). J. J. Berzelius, ‘Ueber das Ozon’, J. Prakt. Chem., 40 (1847), pp. 242–6.
Marchand: Richard Felix Marchand (1813–50). R. F. Marchand, ‘Ueber Ozon’, Poggend. Annal., 67 (1846), pp. 143–4.
I shall not divulge or mention the subject of your labours to any one: see letter 1733.
Please cite as “Tyndall1734,” in Ɛpsilon: The John Tyndall Collection accessed on