نظام الزراعة
Couperus and his family travelled to Europe in 1860. They visited Egypt, Marseille, Paris and Brussels on their way to the Netherlands. They settled at the Prinsengracht 4 (7 November 1860) and later moved to Mauritskade 11. Here Couperus wrote a brochure, called "Een woord ter gelegenheid der op handen zijnde ontmoeting der oud Gouverneurs-Generaal J.J. Rochussen en Mr. A.J. Duijmaer van Twist op het veld van vrijen arbeid" (a contribution on the occasion of the meeting between former Governor-Generals J.J. Rochussen and mr. Albertus Jacobus Duymaer van Twist about free labour). Couperus wrote his brochure on the occasion of the session of the House of Representatives, held 15, 16 and 17 October 1860, where the issue of the regulation of the sugar industry was discussed. Mr. Duymaer van Twist declared here that he wanted to reconsider free labour and free industry. In his brochure Couperus intended to give legal guidelines according to which the transition into free labour and free industry should take place. He also resisted the broad discussions that took place, where the way to follow was, in his view, already recorded in these legal guidelines. Couperus wrote: "To what extent will both former Governor-Generals remain into the limits of the already described legal laws? Will they not exceed the regulations? Will they not, as previously seen, prefer their personal views on this subject above the law? " He also wrote that the Dutch government only had the objective to terminate the Cultivation System and to proceed with free labour when was proven that by means of five purification measures, determined by the government, and applied during a slow transition state, the Cultivation System was no longer maintainable and inefficient. He ordered a strict and rigorous application of the rules and strict control by the government and rejected a more loose approach, where things such as mutual agreements regarding landownership by natives were no longer clear. This landownership by natives and revision of laws regarding landownership were very important during the transition state into a new economic system.