Kellgren was centered in London for a while, and that is where the Clemens
family first met him.

The Wellcome Library in London has some Kellgren artifacts, and their online
biography tells us this about his comings and goings:

"[Jonas] Henrik Kellgren (1837-1916) was a practitioner of Swedish medical
gymnastics and helped to disseminate the technique beyond Sweden. He was
born in Alingsas, southern Sweden, matriculated in 1855 and became an
officer in the Swedish Army in 1858. In 1863-1865 he trained at the Kungliga
Gymnastika Centralinstitut in Stockholm (founded 1813 by Per Henrik Ling,
the pioneer of medical gymnastics), gaining the institute's diploma, and
took up the post of teacher of pedagogical gymnastics at Lidköping.
Following the death of his wife and son, however, he left Sweden and settled
in Germany, setting up the Schwedisches Heilgymnastisches Institut in Gotha.
In the early 1870s his health broke down and he retired from full-time work,
taking up residence in London. Here he founded the Swedish Institution for
the Cure of Diseases by Manual Treatment. An expanding practice was
reflected in the foundation of further institutes in the German resorts of
Norderney (1877) and Baden-Bad!
 en (1883), and in Paris (1884); in summer he took patients to Sanna, near
Jönköping in Sweden, leading to the foundation of a sanatorium there. He
became the director of the Kungliga Gymnastika Centralinstitut in Stockholm.
His son-in-law, Edgar Ferdinand Cyriax, who took up residence in London, was
also an important figure in the spread of Kellgren's techniques of Swedish
remedial gymnastics and massage to the United Kingdom."

So, the Sanna in question was "near Jönköping," if that helps. And his
activities there were only a summertime occurrence, it seems.

Here's a little Kellgren background as it pertains to the Clemens family,
for those who may not be familiar with him:

When they first heard about Kellgren, he was in London, so the Clemens
family went from Vienna to London, where they arrived on June 3, 1899. By
the end of the month, they were so impressed by the benefits of Kellgren's
methods that they spent the rest of the summer (July through August) in
Sanna, Sweden, at Kellgren's sanatorium by a lake.

At first, it looked as though Kellgren's methods were impressively
successful.

Clemens wrote to William James: "It is my conviction that Kellgren can
modify any ailment, & can cure anything that is curable."

He wrote to Henry Rogers: "I have a very good time here experimenting with
the system in my own person and watching the patients. I wish you were here
and had about a hundred diseases to experiment on, so that I could keep the
record. They would knock them out of you as fast as you could call game."

So, if you have any luck finding anything, let us know!

Pat Ober