Nevertheless, under that sky brilliant with pure light, in that atmosphere of freshness of perfume and of harmony, it seemed to me that a tint of infinite melancholy was everywhere diffused. I regarded the glorious sky, I listened to the trembling foliage, I breathed the penetrating odors, but something was everywhere wanting. When I sought what it was that I missed, I found it was the trees of my native land, which do not grow in every zone, and where they do grow are not so fine as here. I instinctively sought the wide-spreading oak, the lofty walnut, the chestnut with its tender verdure, the tall slender poplar, the modest willow, and the birch with its light shadow. I recalled the odor of their foliage, associated with my dearest remembrances, but in vain. I felt then an immense and inexpressible void that nothing could fill, and tears naturally sprang from these vague and profound impressions. {84} I hungered, I thirsted for the odor of the trees that had overshadowed my infancy--an insatiable hunger, a thirst nothing could satisfy. On returning from that remote voyage, especially during the first weeks, I went to the nursery of the Luxembourg, (alas! poor nursery!) I sought the fresh shades of the Bois de Boulogne, and there, during long rambles, I crushed the leaves in my hands and inhaled the perfume they gave out. I felt my lungs expand, as if a new life was infused into them with the odor I breathed. This invisible aliment which we derive from the exhalations of the plants to which we have been accustomed from infancy, had become for me an absolute necessity, a condition of health. A climate, a country may not at all times be favorable to longevity, or at all times unhealthy. The predominance of one industrial pursuit over another, the choice of one material instead of another for building houses, or a sudden change in the general habits, necessarily modifies, in a great degree, the conditions of longevity. This is what has happened in the Isle of Bourbon. Till within a few years, no epidemic or contagious malady was known in that fortunate island; no fever, no cholera, no throat complaints, no small-pox, etc. But all these diseases have attacked its inhabitants since our manures, our materials for building, and our products in general, have been used by them in large quantities.