982 OF THE BRANCHES OF THE HUMAN FAMILY. 



whether the remote effect is not of a reverse nature. 1 Their modus operandi, 

 when they are really beneficial, seems to lie in promoting the digestive pro- 

 cess, and in thus aiding in the appropriation of those nutritive materials 

 which constitute the real source of the solid constituents of the milk. 



82.0. The influence of various Medicines upon the milk is another important 

 question, which has not yet been sufficiently investigated. As a general rule, 

 it appears that most soluble saline compounds pass into the milk as into other 

 secretions; but there are many exceptions. Common salt, the sesquicarbo- 

 nate of soda, sulphate of soda, iodide of potassium, oxide of zinc, trisnitrate 

 of bismuth, and sesquioxide of iron, 2 have been readily detected in the milk, 

 when these substances were experimentally administered to an Ass ; and 

 ordinary experience shows that the Human infant is affected by many of 

 these when they are administered to the mother. The influence of mercurial 

 medicines taken by the mother, in removing from the infant a syphilitic 

 taint possessed by both, is also well known. The vegetable purgatives, espe- 

 cially castor oil, senna, and colocynth, have little effect upon the milk ; 

 hence they are to be preferred to the saline aperients, when it is not desired 

 to act upon the bowels of the child. 



CHAPTER XIX. 



OF THE DIFFERENT BRANCHES OF THE HUMAN FAMILY, 

 AND THEIR MUTUAL RELATIONS. 



1. General Considerations. 



821. ON taking a general survey of the Human race, it is natural, in the 

 first place, that we should proceed to inquire into the evidence at present 

 possessed of its antiquity, and into the physical and social conditions which 

 prevailed in the most remote periods of which any information can be ac- 

 quired ; and secondly, that we should endeavor to ascertain whether the origin 

 of the race is attributable to a single pair whose offspring have peopled the 

 earth, or whether there may not have been a plurality of parents or of 

 centres from which the remarkably different nations that are now in exist- 

 ence have sprung. The question of the remote Antiquity of Man, though 

 long ago suggested, has only of late years, on account of the numerous facts 

 which seem to lend support to it, awakened a lively spirit of philosophic 

 inquiry. When our attention has been directed to it, however, it soon ap- 

 pears that no subject possesses a deeper interest than the relation in which 

 Man stands to the organic world around him both animal and vegetable; 

 whether he was originally created with his corporeal powers, and the intel- 

 lectual faculties to which they minister already developed to their highest 

 extent, and capable of the greatest results that have been achieved in sub- 

 sequent times ; or whether he is not rather to be regarded as the crown and 

 acme of a long process of development commencing with far simpler organ- 

 isms, which, under the protracted operation of external agents, and in 

 accordance with the law of continuous descent with modification through nat- 



1 Se the Author's Physiology of Temperance and Total Abstinence, $ 208. 



2 See Bistrow, On the'Passage of Iron into the Milk, Virchow's Archiv, xlv, 98. 



