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Darwin Correspondence Project

From J. B. Hannay   27 June 1881

Private Laboratory, | Sword Street, | Glasgow.

27th June 1881

Dear Sir

The suggestion contained in your letter of the 22nd for which I thank you very much is one which I shall shortly put to practical test.1 My great difficulties have been in obtaining vessels strong enough to withstand the pressure at high temperatures, and my troubles are not yet over as I find that nearly all matter is permeable to gases at such high temperatures when under great pressure– – – –2 A fact which may have some interest for you has come under my notice lately that Albumen may be heated to the melting point of glass without decomposition provided sufficient pressure be employed so that I can try the effect of other bodies with it. I have recently shown that in ordinary fluids the liquid and gaseous states are clearly separated and not continuous as Andrews supposed; but when we come to such complex bodies as albumen we have a new state which I think is the convergence of the three states of matter at one point.3 We know that the simpler the compound the greater is the contraction due to chemical union and the greater is the difference between the volumes of the liquid and vapour of such a compound. In a very complex molecule such as albumen we have almost no contraction upon combination and could albumen be converted into vapour by boiling we would find that it would pass to vapour without expansion—in fact the two states are merged in abumen and it partakes both of the character of liquid and gas and perhaps also solid. This may account for the peculiar property of living matter in virtue of which it can absorb matter of a like nature for food much in the same way as one gas diffuses into another. The investigation of protein substance in the manner I am doing enables me to watch changes which cannot be studied by ordinary chemical methods and I may be able to intelligently reverse processes which have taken very long periods for their completion viz:—the formation of structural compounds. The field I have entered upon is extremely fertile and of such vast extent that I shall only endeavour to give others a glimpse of a few paths to tempt them to follow me.

I am Dear Sir | Very Faithfully Yours | J B Hannay

Footnotes

Several of Hannay's attempts to produce artificial diamonds had ended when the iron tubes in which he heated material under pressure exploded (Revie 1980).
Depending on its composition, the melting point of glass is between 1400°C and 1600°C; the decomposition temperature of egg albumin under normal pressure is 60°C. Thomas Andrews, in his article ‘On the continuity of the gaseous and liquid states of matter’ (Andrews 1869, p. 588), had stated that at 35.5°C and 108 atmospheres, carbonic acid was nearly midway between a liquid and gaseous state and that there was no valid reason for assigning it to one form or the other. Hannay countered this view in his paper ‘On the limit of the liquid state’, concluding that the liquid state had a limit, which was an isothermal passing through the critical point (Hannay 1881, p. 522).

Bibliography

Andrews, Thomas. 1869. The Bakerian lecture: On the continuity of the gaseous and liquid states of matter. [Read 17 June 1869.] Philosophical Transactions of the Royal Society of London 159: 575–90.

Hannay, James Ballantyne. 1881. On the limit of the liquid state. [Read 10 March 1881.] Proceedings of the Royal Society of London 33 (1881–2): 294–321.

Revie, James. 1980. The case of the Hannay diamonds. New Scientist, 21 February 1980, p. 591.

Summary

Experiments on change of state in albumen under high temperature and pressure.

Letter details

Letter no.
DCP-LETT-13222
From
James Ballantyne Hannay
To
Charles Robert Darwin
Sent from
Glasgow
Source of text
DAR 166: 99
Physical description
ALS 5pp

Please cite as

Darwin Correspondence Project, “Letter no. 13222,” accessed on 28 March 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-13222.xml

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