POPULAR MISCELLANY. 



57i 



capable of undergoing that fermentation. 

 The human body may be considered as such 

 a substance, and we may conceive of a water 

 containing such organisms which may be as 

 pure as can be as regards chemical analysis, 

 and yet be, as regards the human body, as 

 deadly as prussic acid. This is a terrible 

 conclusion, but it is true ; and, if the public 

 are guided by percentages alone, they may 

 often be led astray. The real value of a 

 determination of the quanfity of organic 

 impurity in a water is that by it a shrewd 

 notion can be obtained as to what has had 

 access to that water. If it be proved that 

 sewage has been mixed with it, there is a 

 very great chance that the excreta of some 

 diseased person may be there also. On the 

 other hand, water may be chemically gross, 

 and yet do harm to no one, the great danger 

 being in the disease-germs. 



Man in America. Professor Flower, in 

 a recent lecture on the " Anatomy of Man," 

 . before the Royal College of Surgeons, Lon- 

 don, discussed at some -length the question 

 of his origin on the American Continent. Till 

 recently, opinions on the early peopling of 

 America had been divided between the views 

 that the inhabitants of this continent were 

 a distinct indigenous people, and therefore 

 not related to those of any other land ; and 

 that they were descended from an Asiatic 

 people who, in comparatively recent times, 

 passed into America by the way of Behring 

 Strait, and thence spread gradually over the 

 whole Continent. These theories have had 

 to undergo considerable modifications in 

 consequence of the discovery of the great 

 antiquity of the human race in America, as 

 well as in the Old World. The proof of 

 this antiquity rests upon the high and inde- 

 pendent state of civilization which had been 

 attained by the Mexicans and Peruvians at 

 the time of the Spanish conquest, and the 

 evidence that that civilization had been pre- 

 ceded by several other stages of culture, fol- 

 lowing in succession through a great stretch 

 of time. The antiquity of this quasi-his- 

 torical period is, however, entirely thrown 

 into the shade by the evidence now accumu- 

 lating from various parts of North and South 

 America, that man existed on the Western 

 Continent, and under much the same condi- 

 tions of life, using precisely similar weapons 



and tools, as in Europe during the Pleisto- 

 cene or Quaternary period, and perhaps 

 even farther back in time. Recent paleon- 

 tological investigations show that an im- 

 mense number of forms of terrestrial ani- 

 mals, that were formerly supposed to be 

 peculiar to the Old World, are abundant in 

 the New. Taking all circumstances into 

 consideration, it is quite as likely that Asi- 

 atic man may have been derived from Amer- 

 ica as the reverse, or both may have had 

 their source in a common center, in some 

 region of the earth now covered with sea. 



Illusions and Apparitions. All illusive 

 visions and apparitions are susceptible of a 

 scientific explanation. They originate in 

 some derangement of the brain and nervous 

 system, and are for that reason most likely 

 to occur to persons who are out of health. 

 The apparent reality of some of these illu- 

 sions is often wonderful, and might well 

 prompt those who are not acquainted with 

 nervous physiology, or who have not devoted 

 careful attention to the subject, to refer 

 them to something out of the common. 

 Even while we are in perfect possession of 

 our faculties, we imagine that we see objects 

 before us as clearly as though they were 

 actually present, or hear, with equal distinct- 

 ness, sounds which have no real existence 

 outside of ourselves. The explanation may 

 be found in a simple study of the physiology 

 of the nervous system, and shows that the 

 illusions have a material basis. Our sensa- 

 tions are transmitted from the organ that re- 

 ceiyes them to the brain, and it is the brain, 

 not the organ, that experiences them and is 

 their seat. In the case of sight, it is the func- 

 tion of the eye to receive and adjust the rays 

 of light coming from the object that we see, 

 so that they shall produce an impression on 

 the brain. The eye represents the lenses of 

 the photographer's camera; but the brain 

 corresponds to the sensitive plate which re- 

 ceives the image, and on which all subsequent 

 alterations of the image are effected. Similar 

 relative parts are played by the organs and 

 the brain in the case of the other senses. 

 Now, if a similar impression to that which 

 is transmitted to the brain from the organ 

 of sense is produced upon it by any other 

 cause, the same kind of a sensation will 

 result. This may happen when the brain 



