In general, any method which fixes the attention upon a single stimulus long enough is probably sufficient to produce Hypnosis; but the result is quick and profound in proportion as the patient has the idea that it is going to succeed, i. e., gets the suggestion of sleep. It may be said, therefore, that the elaborate performances, such as passes, rubbings, mysterious incantations, etc., often resorted to, have no physiological effect whatever, and only serve to work in the way of suggestion upon the mind of the subject. In view of this it is probable that any person in normal health can be hypnotized, provided he is not too sceptical of the operator's knowledge and power; and, on the contrary, any one can hypnotize another, provided he do not arouse too great scepticism, and is not himself wavering and clumsy. It is probable, however, that susceptibility varies greatly in degree, and that race exerts an important influence. Thus in Europe the French seem to be most susceptible, and the English and Scandinavians least so. The impression that weak-minded persons are most available is quite mistaken. On the contrary, patients in the insane asylums, idiots, etc., are the most refractory. This is to be expected, from the fact that in these cases power of strong, steady attention is wanting. The only class of pathological cases which seem peculiarly open to the hypnotic influence is that of the hystero-epileptics, whose tendencies are toward extreme suggestibility. Further, one may hypnotize himself--what we have called above Auto-suggestion--especially after having been put into the trance more than once by others. When let alone after being hypnotized, the patient usually passes into a normal sleep and wakes naturally. It is further evident that frequent hypnotization is very damaging if done by the same operator, since then the patient contracts a habit of responding to the same class of suggestions; and this may influence his normal life. A further danger arises from the possibility that all suggestions have not been removed from the patient's mind before his awaking. Competent scientific observers always make it a point to do this. It is possible also that damaging effects result directly to a man from frequent hypnotizing; and this is in some degree probable, simply from the fact that, while it lasts, the state is abnormal. Consequently, all general exhibitions in public, as well as all individual hypnotizing by amateurs, should be prohibited by law, and the whole practical application as well as observation of Hypnosis should be left in the hands of physicians or experts who have proved their fitness by an examination and secured a certificate of licence. In Russia a decree (summer, 1893) permits physicians to practise hypnotism for purposes of cure under official certificates. In France public exhibitions are forbidden.