The subject is too vast to be dealt with in even the longest answer to correspondents, and we can only say here to “Mercia,” “The Would-be Wise One,” and “Nothing but Leaves,” that we have begun in this volume a series of articles by Lily Watson on “Self-Culture for Girls,” which deal practically and in detail with the books that should be read, the method of studying them, and everything that girls anxious to make the best of their opportunities can wish to know. ANSWERS TO CORRESPONDENTS. MEDICAL. LITTLE DOT.--1. The condition of your face is almost for certain due to _acne rosacea_. The only other disease which we think it likely that you could be suffering from would be _lupus erythematosus_--a form of lupus which is not due to tuberculosis or scrofula, but which is a highly-developed form of chilblains. Your description agrees so well with that of _acne rosacea_ that there can be little doubt but that it is that complaint. This disease would be in no way dependent upon nor influenced by any disease that your parents may have had. This complaint commonly goes by the name of “grog-blossoms”; but is frequently caused by other things than “grog.” In fact it is not the alcohol itself so much as the indigestion that it causes which produces the “blossoms.” Any form of indigestion may be accompanied by rosacea; and so the first thing in the treatment of the affection is to look to the digestion. Locally use an ointment of sulphur or ichthiol, preferably the latter. You must guard carefully against constipation, as this of itself will produce rosacea.--2. We think it highly improbable that you suffer from stone in the kidney; but of course we could not be certain without personal examination. The only symptom you give us is one which you are very likely to have misinterpreted, whereas you tell us nothing which to our minds suggests kidney disease. MARGARET.--You _can_ test for yourself whether the water supplied to you contains lead; but it is hardly worth your while to do so. Still, if you wish to try, get a glass cylinder two feet long, and place it on a sheet of white paper. Fill it with the water to be tested, and pour into it a few drops of solution of sulphuretted hydrogen, or let a jet of the pure gas bubble through the water. If lead is present a brownish discoloration of the water will occur, varying in depth of tint according to the amount of lead present. Copper and one or two other metals give the same reaction. You must be careful of the sulphuretted hydrogen, for it is poisonous. You could get the water tested for less money than the cylinder and reagent cost to buy.