CORNFLOWER.--Starch, being one of the chief foods of man, cannot be injurious to the blood. If taken in excess it has a tendency to make you fat. It is most undesirable to get into the habit of sucking alum, for this drug has an exceedingly injurious effect upon the stomach and bowels. Chalk will cause indigestion and constipation. This habit of taking chalk, starch, etc., is due to what is sometimes called depraved appetite, but it is most commonly merely a silly habit, easily broken by a little determination. ANXIOUS.--You certainly suffer from some trouble with your lungs and need further treatment. You had far better see a skilled physician and have your chest thoroughly overhauled. From your letter, we think that you would obtain great advantage from spending the winters abroad, if you can do so. But do nothing until your chest has been examined. E. H.--That we do not write for London girls only is abundantly proved by this correspondence column. We have this morning answered letters from all of the five continents. In fact, very few of our medical correspondents are Londoners, which is not surprising, for medical advice is so easy to obtain in the great Capital. Most of our correspondents live in out-of-the-way places--very many in the Australian bush or North American prairies. Of course, the science of medicine is much the same all over the world, and the advice that we give to a person in London is usually applicable to everyone suffering from the same affection in Europe, Asia, Africa or America.