to the stinging criticism of the mice the more readily since we had accomplished our main purpose—the clearing up of the question to ourselves. Of the scattered writings on various subjects in which we presented our views to the public at that time, I recall only the "Manifesto of the Communist Party" written by Engels and myself, and the "Discourse on Free Trade" written by myself. The leading points of our theory were first presented scientifically, though in a polemic form, in my "Misère de la Philosophie, etc." directed against Proudhon and published in 1847. An essay on "Wage Labor," written by me in German, and in which I put together my lectures on the subject delivered before the German Workmen's Club at Brussels, was prevented from leaving the hands of the printer by the February revolution and my expulsion from Belgium which followed it as a consequence.
The publication of the "Neue Rheinische Zeitung" in 1848 and 1849, and the events which took place later on, interrupted my economic studies which I could not resume before 1850 in London. The enormous material on the history of political economy which is accumulated in the British Museum; the favorable view which London offers for the observation of bourgeois society; finally, the new stage of development upon which the latter seemed to have entered with the discovery of gold in California and Australia, led me to the decision to resume my studies from the very beginning and work up critically the new material. These studies partly led to what might seem side questions, over which I nevertheless had to stop for longer or shorter periods of
