It is difficult to see what this or that reason or objection has to do with the subject, except where the laws of population are set at defiance, which is not the case in China. Food and work, peace and security, climate and fertile soil, not universities or steamboats, are the encouragements needed for the multiplication of mankind; though they do not have that effect in all countries (as in Mexico and Brazil), it is no reason why they should not in others. There are grounds for believing that not more than two-thirds of the whole population of China were included in the census of 1711, but that allowance cannot be made for Ireland in 1785; and consequently, her annual percentage of increase, up to 1841, would then be greater than China, during the forty-two years ending with 1753. McCulloch quotes De Guignes approvingly, but the Frenchman takes the rough estimate of 333,000,000 given to Macartney, which is less trustworthy than that of 307,467,200, and compares it with Grosier’s of 157,343,975, which is certainly wrong through his misinterpretation. De Guignes proceeds from the data in his possession in 1802 (which were less than those now available), and from his own observations in travelling through the country in 1796, to show the improbability of the estimated population. But the observations made in journeys, taken as were those of the English and Dutch embassies, though they passed through some of the best provinces, cannot be regarded as good evidence against official statistics. Would any one suppose, in travelling from Boston to Chatham, and then from Albany to Buffalo, along the railroad, that Massachusetts contained, in 1870, exactly double the population on a square mile of New York? So, in going from Peking to Canton, the judgment which six intelligent travellers might form of the population of China could easily be found to differ by one-half. De Guignes says, after comparing China with Holland and France, “All these reasons clearly demonstrate that the population of China does not exceed that of other countries;” and such is in truth the case, if the kind of food, number of crops, and materials of dress be taken into account. His remarks on the population and productiveness of the country are, like his whole work, replete with good sense and candor; but some of his deductions would have been different, had he been in possession of all the data since obtained.[161] The discrepancies between the different censuses have been usually considered a strong internal evidence against them, and they should receive due consideration. The really difficult point is to fix the percentage that must be allowed for the classes not included as taxable, and the power of the government to enumerate those who wished to avoid a census and the subsequent taxation. ~POSSIBILITIES OF ERROR.~