With feelings of mutual mistrust and hostility, commerce was long conducted by Europeans and Chinese at Canton. The question of foreign exemption from local jurisdiction only came up for discussion in cases of homicide; but in every instance the Chinese insisted on their right to punish the murderer. Foreign resistance to the claim was based only on the unwillingness of the Chinese to distinguish between killing by accident, in self-defence, or from malice. In the Chinese code such distinctions exist; but life for life was the inexorable demand when a native was slain by a foreigner; it was not, however, so much jealousy of foreign jurisdiction, as a desire of revenge, that actuated them, as was shown on many occasions. Whenever foreigners tried and executed one of their number for a murder of a Chinaman, the mandarins and people were satisfied. It was the practice of the local authorities to make a representation to the emperor to the effect that such trials and executions were in obedience to their orders, the foreigners being their submissive agents. The real difficulties occurred when an accidental or extenuating homicide took place, or where there was insufficient proof of the guilt of the accused. The condign punishment of those convicted did not meet the requirements of the Chinese authorities. They seized, and held as hostages, countrymen of the murderer, and demanded blood for blood, seeking not justice but revenge. The object was explicitly expressed by the emperor Kienlung, in an edict (1749): 'It is incumbent to have life for life, in order to frighten and repress the foreigner.' Four years subsequent to the issuing of the edict of Kienlung, the Canton local government memorialized the emperor to disallow to foreigners the privilege of appeal, when sentenced to death. Except in times of insurrection no Chinaman can be executed until his death warrant is signed by the emperor. In compliance with that memorial, foreigners, guilty of homicide, were outlawed. It was formally announced that 'The barbarians are like beasts, and not to be ruled on the same principles as citizens. Were any to attempt controlling them by the great maxim of reason, it would tend to nothing but confusion. The ancient kings well understood this, and accordingly ruled barbarians by misrule. Therefore, to rule barbarians by misrule is the true way of ruling them.' It suited the purpose of European residents at Canton to descant upon the arrogance and inhumanity of the Chinese, as manifested by proceedings based upon those hostile edicts, while the provocations which explained and extenuated them were studiously concealed.