it naturally tends to suggest. In like manner the feast of ingatherings, to prevent moralizing on the fall of the leaf. Simili modo, the military, who are daily threatened with destruction, are your only men of perpetual gaiety, who complete the parallelogram of dissipation. "Not a cranny crank or crevice of his crazed cranium, but is crammed and crayoned with a crowd of crusts, crumbs, and crudities, of creekers cribbage and cricket, crabbed crambos and craven crapulency." I believe I have got you to the dictionary with my c's. Well, we should always be learning something; for, as the pick-pocket in the play says, Every lanes end, every shop, church, session, hanging, yield a careful man work. Be not, therefore, unthrifty to your knowledge, as the same pocket-picking pedlar says, but note down and pocket up every thing that can possibly serve the purpose; for it is not in the way of study, but in the way of the world, that materials are to be sought for. Be more than ever on the look-out for speculations, and on the look-in too. It is wonderful how much one may gather out of himself by a long, and close, and nice attention. I am afraid we shall not be so soon at work as this time twelvemonths. Materials come in but slowly; and it is really a matter of much time and thought to compose in such a style and manner as not to be ashamed of it, ADDISON had travelled, and STEELE had been in the army, before they published; but in this our progress will determine us. I have one piece made, but not reduced to style or order, and is at present only in the form of a club discourse. I am very happy you are yoked with the amotary passion, and very impatient to peruse your lucubration; you must search the matter very deep, if I have not the honour to subjoin notulæ quædam ; But what have you to do with anxious love? Away! it is not for men of your kidney. Persevere and scrutinize the passion; but you have no right to meddle with anxious love. Yours, &c. No. XXIII. Mr WILLIAM SMELLIE to ****** DEAR SIR, You are pleased to observe, that I only answered the first page of your last. In re turn, you have sharply hit me off, by taking notice of only one single query out of a dozen. No more quartos; I hate them abominably. Let folio be the word! I scorn to make reprisals; and I shall, therefore, give you my thoughts upon hard and soft water, than which I know not a more difficult theme. In order to this investigation, I must call in the assistance of a few chemical terms, which I shall endeavour to bring down to the level of your slender capacity †. WATERS are divided into pure and impure; or, in other words, into such as are, and such as are not, impregnated with fossile substances. It is from hence easy to conceive, that those waters which run along hard channels, This, it is to be noticed, was in the infancy of chemistry; before our great BLACK gave the first example of accurate analysis, so excellently followed by the celebrated BERGMAN and SCHEEL; and, in consequence of the verification of the discoveries of BLACK, CAVENDISH, and PRIESTLEY, the illustrious and unfortunate LAVOISIER in a manner created a new science, out of a chaotic mass of ancient nonsense and modern confusion. Our readers will be pleased to notice, that this expression is in the unreserved freedom of friendly correspondence; and that his correspondent had declared his unacquaintance with such principles of chemistry as were then known, at that time almost exclusively attended to by medical students. or trickle through the hollow cavities of rocks, must of necessity be more free from pollution than those which sink down into the bowels of the earth, and there prostitute themselves to every strumpet they grapple with in their dark and oblique courses. It is the impregnated waters alone that obstruct the washing of clouts and the scraping of beards, by refusing to combine with soap. SELENITE is a saline substance very universally diffused through the different strata of the earth, and is composed of a calcareous earth combined with vitriolic acid *. It is a distinguishing property of all the acids to unite with alkalis, as with pot-ashes for instance, preferably to any other substance; insomuch that if an acid is applied to any other body containing an alkali, it will extract that alkali, and decompose the subject with which the alkali was formerly joined, provided it was not coupled with an acid of as great strength as the one which was ap This was the ordinary, but erroneous, hypothesis of the times, which conceived the earthy impregnation in hard waters to be se lenite, or sulphat of lime; now well known to be supercarbonat of lime. plied. Hard water is found, by actual experiment, to be impregnated with selenitic salt; i. e. calcareous earth combined with vitriolic acid. Thus far concerning its composition. o account for the effect is, I know, the thing you gape for. O! what a mortifying virtue is humility. You must exercise pa tience, till I give you sufficient legs to walk upon. ALTHOUGH alkalis attract acids preferably to all other substances, yet they unite in a slighter degree with the oil or fat of animals. Soap is a body compounded of alkali and fat. Now is the mist dispelled and the way clear. When soap is attempted to be dissolved in hard water, which, as I said before, is always impregnated with the vitriolic, the strongest of all acids, the consequence must infallibly be a decomposition of the soap; or, to speak more intelligibly, the acid which is dispersed through the hard water attracts and unites with the alkali which is contained in the soap, and leaves the tallow floating in the form of globules upon the surface of the water. Do you understand this solution of your query? To a mere tyro in chemisty it would be perfectly obvious. Set your thoughts upon che, |