Cases known to the Author--Opinion of an English linguist--Family conditions--An Englishman who lived forty years in France--Influence of children--An Italian in France--Displacement of one language by another. English lady married to a Frenchman--An Italian in Garibaldi's army--Corruption of languages by the uneducated when they learn more than one--Neapolitan servant of an English gentleman--A Scotch servant-woman--The author's eldest boy--Substitution of one language for another--In mature life we lose facility--The resisting power of adults--Seen in international marriages--Case of a retired English officer--Two Germans in France--Germans in London--The innocence of the ear--Imperfect attainment of little intellectual use--Too many languages attempted in education--Polyglot waiters--Indirect benefits. My five propositions about learning modern languages appear from your answer to have rather surprised you, and you ask for some instances in illustration. I am aware that my last letter was dogmatic, so let me begin by begging your pardon for its dogmatism. The present communication may steer clear of that rock of offence, for it shall confine itself to an account of cases that I have known. One of the most accomplished of English linguists remarked to me that after much observation of the labors of others, and a fair estimate of his own, he had come to the rather discouraging conclusion that it was not possible to learn a foreign language. He did not take account of the one exceptional class of cases where the family conditions make the use of two languages habitual. The most favorable family conditions are not in themselves sufficient to _ensure_ the acquisition of a language, but wherever an instance of perfect acquisition is to be found, these family conditions are always found along with it. My friend W., an English artist living in Paris, speaks French with quite absolute accuracy as to grammar and choice of expression, and with accuracy of pronunciation so nearly absolute that the best French ears can detect nothing wrong but the pronunciation of the letter "_r_." He has lived in France for the space of forty years, but it may be doubted whether in forty years he could have mastered the language as he has done if he had not married a native. French has been his home language for 30 years and more, and the perfect ease and naturalness of his diction are due to the powerful home influences, especially to the influence of children. A child is born that speaks the foreign tongue from the first inarticulate beginnings It makes its own child language, and the father as he hears it is born over again in the foreign land by tender paternal sympathy. Gradually the sweet child-talk gives place to the perfect tongue and the father follows it by insensible gradations, himself the most docile of pupils, led onward rather than instructed by the winning and playful little master, incomparably the best of masters.