Much of the year 1878 was spent by Zola in making preparations for that book. Incredible as it may seem, his critics have actually reproached him for his previous ignorance of the "successful" Parisian courtesan. His knowledge of her had certainly been limited to her out-door life; like others he had seen her, elbowed her at the theatres, in the Bois, and at other places of public resort. That was all. He therefore applied to friends and acquaintances for information. Edmond de Goncourt, who had repeatedly dined at the table of La Païva[18] before she became the wife of Henckel von Donnersmarck, gave him a variety of information; Ludovic Halévy initiated him into the _demi-mondaine_ side of theatrical life, to which, given all his intercourse with Hortense Schneider, Zulma Bouffar, and others, he was the most competent of guides; men of fashion, who had wasted their best years and much of their money among the harlots of the Second Empire, told him tales of their experiences; he visited the house of one _belle impure_ from basement to attic, and he supped at the house of another. Of the lower-class unfortunate he had, perforce, seen a good deal during his bohemian years in the Quartier Latin, and all observers of women of that category are aware that in most cases, though they may acquire some superficial polish on rising to wealth, their real natures undergo little change. Zola's enemies naturally imputed the writing of "Nana" to his partiality for vice and scandal, but those who are acquainted with "L'Assommoir" will recognise that, in such a series as "Les Rougon-Macquart," a study of the courtesan was the necessary corollary of the study on drink and the general degradation of the working class. It is from such homes as those of Coupeau and Gervaise that spring nine-tenths of the unhappy creatures so grimly denominated _filles de joie_. Nana's childhood and youth had already been recounted in "L'Assommoir," and it was certain that Zola would not leave her there. How could he picture the degenerescence of a period if he omitted the harlot, who had played--people hardly seem to recognise it nowadays--such a prominent, such a commanding part, during the years when Napoleon III.--dallying himself with La Castiglione, La Bellanger, and a dozen others, while his cousin Prince Napoleon Jérôme kept the notorious Cora Pearl--had transformed the proud city of Paris into the brothel of Europe? Again, scores of Zola's contemporaries, writers of various degrees, by trying to poetise the courtesan, had increased her influence a hundred-fold, and the time had come to check her encroachments by exhibiting her in her true colours, with all her vulgarity, her greed, her degradation, her shamelessness and heartlessness.