He developed one of the first therapeutic treatments for this pathology[10][11] and a medical device to relieve the respiratory symptoms of the patients: the SPIRO,[12][13][14] in 1934.

He quickly transformed himself into fitness equipment and Jos Jullien reached an agreement with the spa of Salin les Thermes (Savoie) to commercialize his invention.

It was during the visit of the spa that he began to take an interest in the properties of thermal waters, initially as a complement to treatments for patients with Brucellosis.

[15] He conducted his first experiments on the waters of Aix les Bains (Savoie) for application in dermatology, but without success.

In 1946, Adrien Barthélemy bought the small spa town of Molitg-les-Bains in the Pyrénées-Orientales, and contacted Jos Jullien to study the waters of the resort.