Allied to the influence just mentioned is another, to which I will give a passing notice. I refer to the hobby-riding which is so common in the medical profession. Every good thing seems to be destined to this use till it loses its novelty; and therefore its real value can never be accurately ascertained, till it has passed what may be called the _hobby-period_ of its existence. No careful discriminations are made to any extent until this period is finished. Even the experience, which is recorded in journals of medicine during its continuance, needs to be thoroughly sifted by after observation. The influence of this hobby-riding is therefore a great hindrance to the progress of medical science. And this influence is not confined to the particular subjects to which it is applied. It does not merely throw obstacles in the way of _their_ investigation. It is not thus limited and evanescent, for it is counter to the true _spirit of observation_, and impairs its hold upon the profession as a whole. The riding of hobbies is very much regulated by fashion. For there is a fashion in medicine as well as in everything else; and it not only bears rule in the community at large, but it exercises no inconsiderable authority in the medical profession itself. Some particular diseases and modes of treatment, are ever, sometimes one, and sometimes another, uppermost in the popular mind. When anything new comes up in regard to disease or its treatment, which attracts considerable attention, there is a strong temptation to make a hobby of it. Multitudes suppose that they have the disease, and need the treatment. This may be really true of but few of them, but such is their belief. There is no time for accurate discrimination if the object be to make fame and money. If a physician honestly undertakes to decide what cases need the treatment, and what do not, he will not be as successful in gaining eclat, and in getting the people’s money, as his neighbor will be, who catches the popular breeze with all his sails, knowing that it is not wont to blow in one direction for any length of time.