This statute is denounced the butchers not only as creating a monopoly and conferring odious and exclusive privileges upon a small number of persons at the expense of the great body of the community of New Orleans, but it is asserted that it deprives a large and meritorious class of citizens—the whole of the butchers of the city—of the right to exercise their trade, the business to which they have been trained and on which they depend for the support of themselves and their families, and that the unrestricted exercise of the business of butchering is necessary to the daily subsistence of the population of the city.