Lucerne, 1 August 1917

'Surrounded with love and care': Einstein's gratitude to the Bessos.

Einstein expresses intense gratitude to the Bessos for their care for him: 'You have surrounded me with so much love and care that I do not know how I can repay you'. Einstein has been given strict instructions for dealing with his abdominal disorder, which he will follow conscientiously, and his sister and brother-in-law, Maja and Paul Winteler, with whom he is now staying, 'are establishing a sanatorium which is as cheerful as it is meticulous'. His elder son, Hans Albert, has been staying, although he has just returned to Zurich: 'He is developing well, but often behaves rather roughly towards me from old practice'. By chance, Einstein has bumped into an old colleague from the Swiss Patent Office, which brings back happy memories. He isn't working much, although he has heard something interesting about relativity from the Italian mathematician Tullio Levi-Civita, who 'is also interested in the λ-term [the cosmological constant]'; he also mentions an interesting offprint about crystallography sent to him by A.M. Schoenflies.

Einstein had been struck down during his visit to the Bessos with a recurrence of his acute abdominal pains, which Heinrich Zangger diagnosed as duodenitis: the remedies included lying down at the first sign of an attack, and the application of heat.