She first matriculated in the University of Heidelberg, where she spent two years in studying mathematics under the most eminent professors of that famous old institution. Thence she went to Berlin. She could not enter the University there, as its doors were closed to female students; but she was fortunate enough to prevail on the illustrious Professor Weierstrass, regarded by many as the father of mathematical analysis, to give her private lessons. He soon discovered to his astonishment that this child-woman had "the gift of intuitive genius to a degree he had seldom found among even his older and more developed students." Under this eminent mathematician Sonya spent about three years, at the end of which period she was able to present to the University of Goettingen three theses which she had written under the direction of her professor. The merit of her work and the testimonials which she was able to present from Weierstrass, Kirchhoff and others were of such supreme excellence that she was exempted from an oral examination and was enabled, by a very special privilege, to receive her doctorate without appearing in person. Not long after receiving her doctor's degree--one of the first to be granted to a woman by a German university--she was offered the chair of higher mathematics in the University of Stockholm. She was the first woman in Europe, outside of Italy, to be thus honored. But her appointment had to be made in the face of great opposition. No other university, it was urged by the conservatives, had yet offered a professor's chair to a woman. Strindberg, one of the leaders of modern Swedish literature, wrote an article in which he proved, "as decidedly as that two and two make four, what a monstrosity is a woman who is a professor of mathematics, and how unnecessary, injurious and out of place she is."[130] The fame that came to Sonya through her achievements in the German and Swedish universities was immensely enhanced when, on Christmas eve, 1888, "at a solemn session of the French Academy of Sciences, she received in person the _Prix Bordin_--the greatest scientific honor which any woman had ever gained; one of the greatest honors, indeed, to which any one can aspire." She became at once the heroine of the hour and was thenceforth "a European celebrity with a place in history." She was feted by men of science whithersoever she went and hailed by the women of the world as the glory of her sex and as the most brilliant type of intellectual womanhood. Mme. Kovalevsky's printed mathematical works embrace only a few memoirs including those which she presented for her doctorate and for the _Prix Bordin_. But brief as they are, all of these memoirs are regarded by mathematicians as being of special value. This is particularly true of the memoirs, which secured for her the _Prix Bordin_; for it contains the solution of a problem that long had baffled the genius of the greatest mathematicians.