The unwholesome climate of St. Petersburg and the over-straining of her nerves soon showed themselves to have a detrimental effect on the health of the till then so blooming Princess. She could take but little part in the festivities of Christmas-time, and on the 1st of January 1864 she became alarmingly ill of a nervous gastric fever. The Grand Duchess surrounded her with motherly love and care. The Grand Duchess Catherine and the lady-in-waiting, Baroness Edith von Rahden, nursed and watched her unceasingly. But weeks went by, and she still lay in bed. It was the first illness she had ever had. Till now, when she had reached her twentieth year, she had never tasted any medicine. As soon as she was released from pain and could occupy herself, she became absorbed in the book of “The Unconscious Life of the Soul,” which her father had sent her as a Christmas present. She writes from her bed:--“There is such great humility in the preface, combined with the power of assurance. Then I recognised my father in the first three pages by his manner of demonstrating his arguments. What a different sort of reading it is when the language is as familiar to us as our own, when we see the idea before us which we have absorbed as the very breath of our life! I am glad that papa has sent me the book just now. As I read, I see his face before me, and seem to be really talking to him.” On the 16th of January 1864 she wrote to her father:--“How often a feeling of pride comes over me that I have my father’s writings in my hands, and then a glow of happiness, because every word has come from your pen and from your inmost heart! For your soul was prepared by the wonderful experiences of fifty years, and the mind could communicate to her unhindered, and tell her what it will about itself and its nature. It is such a beautiful idea, that the indwelling Spirit of God educates the soul and gives to it as much as it requires. Not a word more. It makes one very humble, and awakes in one a longing to keep the soul so pure (by withstanding its natural earthly temptations), that God may find it worthy of having many things revealed to it! But how is it with the mind and the soul of Christ? That is the mystery of His godly and yet human nature; His soul must have been so pure, so much above earthly things, that God could tell it all things.