His very interesting work, “America Dissected,” was published at Dublin in 1753. It gives us a good idea of the extent of Irish immigration and of other matters in the colonies at that time. The work comprises letters addressed by Dr. MacSparran from Narragansett “in the colony of Rhode Island” to friends in Ireland. Here are extracts from one written by him to Col. Henry Cary, under date of August, 1752: “There has lately been made, upon and behind the mountains of Virginia, a new Irish settlement, by a transmigration of sundry of those that, within these thirty years past, went from the north of Ireland to Pennsylvania. As the soil in that new Irish settlement is natural and friendly to grass, they will for many years to come raise great quantities of neat cattle.” Writing of Maryland he says: “As the late Lord Baltimore was the first Protestant peer of the Calvert family, his predecessors (as it was natural they should) first peopled this province with a colony of Irish Catholics.... There are some Quakers here, in consequence of its bordering on Pennsylvania, and some Irish Presbyterians, owing to the swarms that, for many years past, have winged their way westward out of the great Hibernian hive.” Again referring to Pennsylvania, Dr. MacSparran writes: “The Irish are numerous in this province, who, besides their interspersions among the English and others, have peopled a whole county by themselves, called the county of _Donnegal_, with many other new out-towns and districts. In one of these frontiers, on the forks of Delaware, I assisted my brother (who left Ireland against my advice) in purchasing a large tract of land, which by his wife’s demise, above a year ago, descends to his children. The exportations from this province are principally wheaten flour, which they send abroad in great quantities; and by the accessions and industry of the Irish and Germans, they threaten, in a few years, to lessen the American demands for Irish and other European linens.” Alluding to New Hampshire he continues: “In this province lies that town called London-Derry, all Irish, and famed for industry and riches.” Then, leaving New Hampshire, he continues: “Next you enter Main,[8] which in its civilized government, is annexed to the Massachusetts, as Sagadahock also is; and both rather by use than right. In these two eastern provinces many Irish are settled, and many have been ruined by the French Indians and drove from their homes. It is pretty true to observe of the Irish,[9] that those who come here with any wealth, are the worse for their removal; though, doubtless, the next generation will not suffer so much as their fathers; but those who, when they came, had nothing to lose, have throve greatly by their labour.”