*Nore.— This return has been complied from abstracts of the population of townlands and streets by the several enumerators, which may hereafter be altered in some degree upon revision, but it is apprehended that no change of any very great substance will be necessary.

  The date of the present census being 68 days earlier than that of the preceeding, 5841 persons should be added to the gross populations of 1841, that being the number of harvest labourers who it was ascertained had left Ireland previous to the 7th June in that year.  In the absence, however, of a general system of registration of births and deaths in Ireland, the necessary adjustments in consequence of the change in the periods at which the census of 1841 and 1851 were taken cannot be arrived at.  Neither of these returns include the army serving in Ireland.