Some allusion has already been made to the medical theories respecting clothing that have emanated recently from a celebrated German professor, Dr. Gustav Jaeger, of the Royal Polytechnic School at Stuttgart. His investigations into the subject commenced in the year 1872, and appeared to have been fairly exhaustive in the way of scientific experiment and personal experience, with the result that Dr. Jaeger considers he has discovered that the health of the world in general is much prejudiced by the materials, as well as the forms, in general use. In Germany his views seem to have met with very extensive acceptance; they have revolutionised the trade of Stuttgart, where Dr. Jaeger practises his profession; and many of the leading men—such as Count von Moltke and others—have adopted his clothing; and it seems probable that his principles will be applied to the German army, with the view of promoting the health of the troops. In Italy the first physicians have declared in favor of it, and so universally does the demand appear to have arisen on the Continent, that the present writer found Dr. Jaeger’s garments commonly exposed for sale in Switzerland, at Berne, Lucerne, and Vevey, and other smaller towns. The stall for Dr. Jaeger’s clothing has formed an attraction at the “Healtheries” this season, and, by the formation of a limited company, who have opened a depôt in Fore Street for its sale, those who desire to look into the subject, and form their own opinions, will be able to do so in England. Dr. Jaeger’s reform is not a difficult one, and consists of the fundamental doctrine that, as we are animals, we should wear animal clothing. The physical “reasons why” are—first, that their non-conducting qualities are a guarantee that the temperature of the body shall be in a great measure preserved, while on the other hand the shape and arrangement of their constituent hairs provide for the escape of moisture by capillary attraction; and their adaptation to both these ends is greater than that of any vegetable fabric. In England we have for many years acted instinctively on these conditions, and we have adopted woollen, in the shape of flannel, for use in cricket, boating, tennis, and in any athletic exercises likely to cause profuse perspiration, as being the safest covering to ensure us against cold and the sudden and dangerous chills which are likely to follow overheating in a climate like ours. Our action has been the result of observation and experience, which, however, according to Dr. Jaeger, might have been carried still further and applied more widely still. For this profuse perspiration is simply an intensification of the daily action of the skin, which only ceases with life itself. If this action be imperfect or repressed, fat and water accumulate in the tissues, lowering their powers, and the flesh, which should feel elastic and firm, is flabby, causing many disorders in the general economy of the body.