The uniform results of many experiments, have established the importance of this exercise as an instrument in communicating knowledge to the ignorant, whether young or old. We shall shortly advert to a few of the circumstances connected with these experiments, for the purpose of satisfactorily establishing this. In an experiment made in May 1828, under the direction of the Very Rev. Dr Baird, Principal of the University of Edinburgh, before the Lord Provost, and several of the Professors and Clergymen of that city, nine adult criminals, "taken without regard to their abilities," and who, in the opinion of Governor Rose, "formed a fair average of the usual prisoners," were, in the space of three successive weeks, exercised in whole for eighteen or twenty hours. They were at the end of that time minutely examined in the Chapel of the County Jail, in the presence of the Right Honourable and Reverend Professors and Gentlemen, who formed Principal Baird's committee; and their Report of the experiment and its effects bears, that "the result of this important experiment was, in every point, satisfactory. Not only had much religious knowledge been acquired by the pupils, and that of the most substantial, and certainly the least evanescent kind; but it appeared to have been acquired with ease, and even with satisfaction--a circumstance of material importance in every case, but especially in that of adult prisoners." "The examination evidently brought out only a specimen of their knowledge, and did by no means comprise all that had been acquired by them; but, even though it had constituted the whole amount of their information, the fact that such a treasure had been amassed in three weeks is in itself astonishing. The writer of this Minute was not acquainted with the extent of their acquirements when Mr Gall commenced his operations; but judging from the examination, and from his knowledge of the contents of the books taught, he has no hesitation in averring, that the answers which they gave, arose entirely from information communicated by them. And when he reflects that their answers, being clothed in their own words, guaranteed the fact, that it was _the ideas_ upon which they had seized, and that their knowledge participated in no degree of rote, the conviction to his mind is irresistible, that the universal application of the Lesson System to Prison Discipline, and to adults every where, would be followed by effects incalculably precious to the individuals themselves, and to the improving of society in general."