It is to be hoped that such credulity is not very common--it is difficult to form an estimate as to its prevalence, for it breaks out in different directions in different individuals. The more impudent quack remedies for various diseases have had believers amongst all classes of society--and occasionally some enthusiast bursts out with indignation in a letter to the papers, complaining that men of science or the medical profession neglect their duty to the public and refuse to examine the wonderful cure. In all these cases the cure is either a drug which is perfectly well known and practically worthless for the treatment of the disease for which it is recommended, or--as in the case of the celebrated "blue electricity" and "red electricity" (nonsensical names in themselves) sold by an Italian swindler as a cure for cancer and patronized by aristocratic ladies and the late Mr. Stead--is found to be absolutely non-existent. In this last case the liquid sold in little bottles at a high price was nothing but plain water! A more respectable case was the advocacy a few weeks ago by a correspondent in a morning paper of a common African plant (a kind of basil) as a sure destructive or warder-off of mosquitoes when grown near human habitations, and therefore a protective against malaria. Nothing could have been more emphatic than the declaration of the value of this plant by its advocate. But a few days afterwards a letter appeared from a scientific man, giving an account of careful and varied experiments, already made and published, which show that this basil, although containing in its leaves "thymol," as do some other aromatic herbs, yet neither when grown in quantity nor when crushed and spread out in a room has any effect whatever in checking the access of mosquitoes and other flies! In this case, the reputed medical marvel was to hand: it was dealt with, tested, and, as they say in the old register of the Royal Society, "was found faulty."
THE gradual passage of the race of man from the condition of "beasts that reason not" to that of "persons of understanding and reason" has been an immensely long and a very painful one. It is not yet complete--is far, indeed, from being so--even amongst the most favoured classes of the most highly civilized peoples of to-day. Just as our bodily evolution and adaptation to present conditions is incomplete and exhibits what Metchnikoff has called "disharmonies"--that is, retentions of ancestral structures now not only useless, but even positively injurious--so does the mental condition attained by civilized man (if we do not limit our observation to exceptional instances) exhibit a retention--by means of records and accepted teaching--of beliefs and tendencies which were among the first products of the blundering efforts of human reason, and have caused atrocious suffering to millions of human beings in the long process of mental development. At one time the whole race lived in a world of delusions and fantastic beliefs--the outcome of false or defective observation rather than of false logic. These false conclusions as to many subjects were inevitable as soon as man began to reason at all. It was the necessary and injurious accompaniment of the growing habit of "reasoning" by which the more fortunate races have eventually been brought, step by step, to correct conclusions and a dominant position at the present day. The progress from the almost universal prevalence of an enormous system of preposterous false beliefs or conclusions onward to the triumph of sound knowledge has not only taken an immense period of time, but left whole races of men and large sections of the population--even in those races which have produced individuals remarkable for their power of discovering the truth--still subject to the early erroneous conceptions of natural processes and of man's relation to them.