MY attention has just been called to a letter from Mr. David Forbes which appears in NATURE, Sept. 21, under the head “Newspaper Science,” and in which that gentleman, writing from Boulogne, pathetically describes the emotions with which he read a recent “article” in the Globe on “Krupp's” Gun-manufactory at Essen. I need hardly say how deeply I deplore the shock which I have unwittingly been the agent of inflicting on your distinguished correspondent. It will be some small satisfaction if you will allow me to express the hope that the “desired result” of Mr. Forbes's “reluctant” compliance with the advice of his “medical man,” and most wise resolve “to eschew everything scientific for the next few weeks at least, in order to recruit before the winter labours commenced,” may not be utterly defeated by the perusal of “a specimen of English scientific opinion,” of which I am unhappily the author. It would be a terrible reflection indeed, that a stupid error on my part had, perhaps, imperilled the accuracy and success of Mr. Forbes's “winter labours.” The blunder (or rather blunders) occurred as follows:—I, too, was “knocked up with work,” but being myself a “medical man” naturally only in part carried out my own prescription. I would, for the sake of Mr. Forbes, and the credit of “English scientific opinion” in the estimation of his “French acquaintance,” I had exercised a little more discretion. However, unfortunately, I stumbled on the Krupp factory, and all forgetful of my dilapidated mental condition, wrote a note-paragraph (I never write “articles”), which I vainly imagined might have been innocent and interesting. It is not always possible to compress even the manuscript necessary for a paragraph on to a single sheet of paper, and I grieve to say that after my paper had passed the editorial eye three words forming the connecting link of a sentence must have been dropped. What I intended to say, without the slightest notion of giving a “technical or scientific” opinion, was, “The iron is alloyed in crucibles formed with certain clays and a preparation of plumbago.” The words italicised disappeared in some mysterious way. The next of my idiotic sentences goes onto talk about the crucibles, or “creusets” as, to the great scandal of Mr. Forbes, I ventured to call them. If I could stop here, an humble apology for my fault might, perhaps, serve my purpose, but, alas I have more to answer for. Vaguely dreaming of the foot-pound, I actually wrote kilometre for kilogrammetre, when speaking of the power of the new steam hammer; and, worst of all, I also WROTE “Sheffield Gun Metal.”