Now, what the lungs are to the human body, that the heart is to the soul. It is by the heart that we breathe the spiritual and divine atmosphere that sustains our moral life. This atmosphere is composed of three elements,--truth, goodness and beauty, which envelop and penetrate the soul's substance; as it is the respiratory organ of the mind it follows that for the heart, as well as for the lungs, there is an epoch of development which is dangerous, and which, consequently, demands the greatest possible care; it is the epoch of your age at present. An emotion too vivid, an indiscreet thought, an imprudent glance, is quite sufficient to imperil the interesting and delicate process by which your moral constitution is formed, to accelerate the development of the heart, and thus give to this most important organ a pernicious precocity or a false direction. Your mother, anxious and always trembling for your welfare, guards it with tender solicitude from all the dangers to which it might be exposed. But her vigilance cannot equal that of your guardian angel, nor the care with which he removes you from contact with all that might in any way tarnish the purity of your soul, or trouble its peace and harmony. It is to you that the Holy Ghost addresses these words of the Proverbs: With all watchfulness keep thy heart, because life issueth out from it. [Footnote: Proverbs iv 23.] The heart is, therefore, the seat of the moral life, and as the source is known by the waters that flow from it, so will the moral life partake of the character and bear the impress of the heart whence it proceeds. This is true of youth in general, but more particularly so of young ladies. CHAPTER III. THE HEART OF WOMAN; THE NECESSITY OF REGULATING IT DURING YOUTH. The most humble, most chaste, most holy of women, Blessed Mary ever Virgin, she who is the ornament and glory of her sex who, in consequence of her privilege of being the mother of God, merited to be elevated so high above all creatures, revealed to us the existence of a faculty in the soul, unknown to the philosophers, undiscovered by the saints, unspoken of by the prophets. This faculty is more conspicuous in woman than in man, for it exercises in her a decisive influence which extends over the entire period of her life. Hence, God, "who ordereth all things, sweetly," (Wisdom, viii. 1), desired that its existence should be made known to us by a woman, and that, too, while she was visiting another woman.