When, however, he took the subject in hand--spending the greater part of 1891 in collecting and classifying materials[16]--his views changed, and he decided rightly to make the battle of Sedan the keystone of the work. The expression _"la débâcle"_ occurs already in Alexis's "Notes d'un Ami," published in 1882, but at a later stage Zola thought of calling his book "La Guerre" ("War"). It is just possible that this was because a couple of French novels bearing the title of "La Débâcle" were in existence already.[17] However, French authors are much less punctilious than English ones with respect to titles, and it would be easy to mention several instances in which the same has been used--by different writers--three or four times over. In any case, Zola reverted to the title of "La Débâcle" as being the most appropriate to his series, signifying as it did the "smash-up" of that imperial _régime_ whose society he had been describing so long; and though charges of plagiarism were so often brought against him, it would not appear that any arose on this occasion. Zola had found "L'Argent" a difficult subject, and now the preparation of "La Débâcle" proved a herculean task for him. He had never witnessed an engagement in the field; military matters were almost as foreign to him as financial ones. He had dealt with them in a few short stories only, such as "Le Capitaine Burle" and "Les Quatre Journées de Jean Gourdon." But he now visited all the battlefields which were to figure in his narrative, he followed the line of march of the Seventh Army Corps, whose sufferings he intended to describe, he studied everything that had been printed and published in France on his subject, and he was fortunate enough to secure a large number of letters and manuscripts in which eye-witnesses recounted one and another episode of the battle of Sedan. Some of those communications emanated from "privates," who set down their own curious personal experiences and often naïve impressions; and for Zola's purpose these were even more valuable than the reports of generals and other officers. What he made of his subject the world knows; of all the books he ever wrote "La Débâcle" has circulated the most widely.