The stipulations were as cold and precise as any of his mathematical equations. In July 1914, Albert Einstein wrote to his first wife, Mileva Maric, the mother of his two sons, laying down a series of conditions under which he would agree to continue their marriage:

''A. You will see to it (1) that my clothes and linen are kept in order, (2) that I am served three regular meals a day in my room. B. You will renounce all personal relations with me, except when these are required to keep up social appearances.'' And: ''You will expect no affection from me . . . You must leave my bedroom or study at once without protesting when I ask you to.''

On Nov. 25, this letter and more than 400 others, most of them never before seen by scholars, will be auctioned at Christie's in New York along with a rare scientific manuscript. This collection of Einstein letters, the most important one ever to go on the block, is expected to sell for $2 million and the manuscript for $250,000 to $350,000.

The correspondence, mainly in German, includes few new revelations. The basic facts of Einstein's first marriage -- his courtship of Mileva, whom some scholars have regarded as crucial in the development of his scientific theory, and his disenchantment with her -- have been known to biographers. But the letters give a fuller, darker picture of the anguished ending of the marriage.

And they provide an extraordinary glimpse into Einstein's emotional life. They reveal the domestic side of Einstein, a sometimes tender yet sometimes brutal husband of Mileva, and a devoted yet sometimes unthinking and cruel father to his sons, Hans Albert and Eduard.