[111] Letters on the state of Ireland, by the Earl of Rosse: London, 1847. _Halliday Pamphlets, vol. 1993_. These letters were originally sent to the _Times_, but that journal having refused them insertion, the noble author published them in a pamphlet. The Rev. Theobald Mathew said, I do not know on what authority, that two millions of acres of potatoes were irrevocably lost, being worth to those who raised them £20 an acre. This estimate would make the loss £40,000,000. [112] _Mayne on the Potato Failure_. The potato crop, for the most part, continued to look well up to the end of July, but the blight had appeared, in the most decided way, during the first half of that month, although not then very apparent to a casual observer. Mr. Mayne, like many persons at the time, attributed the blight to an insect which some called _Aphis Vastator_, others _Thrips minutissima_. There was a glass case in the Dublin Exhibition of 1853, showing this insect feeding on the leaves and stalks of the potato plant. Mr. Mayne and those who agreed with him, seem, in this instance, to have mistaken cause for effect. Indeed the insect, it would appear, was a natural parasite of the potato, and some observers have gone so far as to assert that the _Aphis Vastator_ abounded more on healthy plants than upon those affected with the blight. [113] _Letter to the Duke of Leinster quoted in Irish Census for 1851_. M. Zander, of Boitzenberg, in Prussia, published, about this time, a method by which full sized potatoes could be produced in one year from the seed, and he further stated that the seedlings so produced had resisted the blight. The old idea was, that it took three years to produce full-sized potatoes from the seed. M. Zander's method was tried in various parts of Ireland and England, its chief peculiarity being that the seed was sown on a light hot bed, and the plants so produced were transferred to the ground in which they were to produce the crop. Full-sized potatoes were the result, each plant producing, on an average, 1-1/2 lbs. of potatoes, or rather more than 29 tons to the Irish acre. This method appeared satisfactory to those who interested themselves about it, but it does not seem to have been followed up. [114] Proceedings of the Royal Dublin Society.