DEAR SIR,—When we met lately at the hospitable board of our common friend, Benjamin Allen, Esq., lately elected Professor of Chemistry in the University of London, our conversation turned (if you can pass me the intoxicating favour of remembering it) on the glorious science of chemistry. For me this knowledge has ever possessed irresistible attractions, from the enormous power which it confers of heaping benefits on the suffering race of mankind. Others may rejoice in the advantages which a knowledge of it bestows—the power which can reduce a Hannibal to the level of a drummer boy, or an all-pervading Shakspeare to the intellectual estate of a vestryman, though it cannot at present reverse those processes. The consideration of the destructive as compared with the constructive forces of chemistry was present, as I recollect, to your powerful intellect on the festive occasion to which I refer. “Yes!” you said (permit me to repeat your very words)—“Yes, Count Fosco, Alexander’s morning draught shall make Alexander run for his life at the first sound of the enemy’s trumpet. So much chemistry can achieve; but can she help as well as harm? Nay, can she answer for it that the lemon which Professor Allen, from the best and purest of motives, has blended with this milk-punch, shall not disagree with me to-morrow morning? Can chemistry, Count Fosco, thus thwart malign constitutional tendency?” These were your words, sir, and I am now ready to answer your deep-searching question in the affirmative. Prolonged assiduous application to my Art has shown me how to preserve the lemon in Milk Punch, and yet destroy, or disengage, the deleterious elements. Will you so greatly honour science, and Fosco her servant, as to sup with me on the night of the twenty-fifth, at nine o’clock, and prove (you need not dread the test) whether a true follower of knowledge or a vain babbler signs—in exile—the name of ISIDOR OTTAVIO BALDASSARE FOSCO? * * * * * _From Mr. Pickwick to the Count Fosco_. May 24. MY DEAR SIR,—Many thanks for your very kind invitation. Apart from the interests of science, the pleasure of your company alone would be more than enough to make me gladly accept it. I shall have the enjoyment of testing your milk-punch to-morrow night at nine, with the confident expectation that your admirable studies will have overcome a tendency which for many years has prevented me from relishing, as I could wish, one of the best things in this good world. Lemon, in fact, has always disagreed with me, as Professor Allen or Sir Robert Sawyer will be able to assure you; so your valuable experiment can be put, in my case, to a crucial test.—Very faithfully yours, SAMUEL PICKWICK. * * * * *