IN ALBERT'S SHADOW. The life and letters of Mileva Maric, Einstein's first wife. Milan Popovic. 183pp. Johns Hopkins University Press. $24.95; distributed in the UK by Plymbridge. Pounds 18.50. - 0 8018 7856 X.

Einstein once jokingly referred to himself as a "Jewish saint", an image zealously policed by his executors until the late 1980s. Then, as Einstein's correspondence began to be published in his Collected Papers, the world learnt about Lieserl, his illegitimate daughter whose fate remains a mystery, his affairs, and an attitude to women that was considerably less progressive than his science. The saint was all too human, after all.

As Milan Popovic rightly says in his introduction to In Albert's Shadow, a touching collection of letters from Einstein's first wife, Mileva Maric, to her closest friend, Helene Savic (nee Kaufler), "they chronicle a rare and intimate friendship between two unusual women who lived through truly epochal events in world history". Popovic is Helene's grandson and recalls that even at the age of six he was struck by Mileva's seriousness and was "a little intimidated by her".

Mileva's letters (none of Helene's replies have survived) cover the period from

1899 to 1932 and provide a fascinating insight into her relationship with Einstein, from the intensity of first love to the mundane reality of married life and the realization that the bohemian student with whom she had fallen in love only had room in his heart for physics: "we are unimportant to him and take second place". They had studied physics together, but now she blamed "damned science" for her unhappiness.

Much is left unsaid in these letters, but the silent pain caused by Einstein's affairs can be heard in a heartfelt comment from 1932: "most of the ills in this world come from women", especially, she adds cryptically, those "who know very well how to burrow in the darkness". These letters tell us little that is new about the great physicist and fail to resolve the continuing debate over Mileva's contribution to Einstein's revolutionary theories. But they are memorable because they allow Mileva to tell her story in her own voice -the struggle to overcome ill health and depression and single-handedly to bring up her two sons, one of whom later suffered from schizophrenia. When they divorced in 1919, Einstein was about to become the world's most famous scientist. As Mileva told Helene bitterly, "one gets the pearl, another the box".