ter. Hydrogen, carbon, and oxygen, predominate in milk ; in the last 

 place, it contains several salts, amongst others, muriate of soda, muriate 

 of potash, and phosphate of lime*. 



The presence of the two last of these substances leads to the following 

 considerations. Muriate of potash, as is observed by Rouelle, does not 

 exist in the blood ; the probability is, therefore, that it is not the blood 

 which supplies the mammae with the materials whence the milk is se- 

 creted, muriate of potash being found in greater quantity in milk than 

 muriate of soda. These salts of potash, on the contrary, are found in 

 considerable proportions in the chyle, formed from vegetable substances; 

 which would lead one to think, that milk is furnished by the absorbent 

 system. The phosphate of lime, which is found in smaller quantity in 

 the urine of nurses, and which is wholly determined towards the mammae, 

 was absolutely necessary in a fluid which supplies nourishment to the new 

 being, while the bones become indurated, and all the parts'acquire soli- 

 dity. 



If we now wish to inquire into the causes which render suction neces- 

 sary, and which subject the new born child to this peculiar mode of nu- 

 trition, these causes will be found in the general weakness of its organs. 

 The organs of digestion would have been incapable of extracting, from 

 the aliments, their nutritive parts, these substances not having undergone 

 the due degree of trituration, from the want of teeth and from the im- 

 perfect state of the other organs of mastication,, It was of consequence, 

 therefore, that the mother should perform the preliminary function, and 

 that she should transmit the aliment ready digested!. It is not, however, 

 to be imagined, that the milk passes, without undergoing any change, 

 into the vessels of the child 5 the child digests the milk, and obtains from 

 it, in a short space of time, and without effort, a considerable quantity of 

 nutritious particles, necessary to the rapidity of its growth. 



The connexion between the mother and childis far' from being broken, 

 at the period of birth 5 the relations between them, though not so close, 

 are uot less indispensable. Before birth, the vital power was so limited 

 in the child, that it was necessary it should receive a fluid already anima- 

 lized, and in a state to yield to the function of assimilation and nutrition. 

 When the child has breathed, when its strength is increased, it may be 

 entrusted with a greater share of the process ; it is then sufficient that 

 the aliment should have undergone the first degree of elaboration, within 

 the digestive canal. But it is not merely to assist in preparing its food, 

 that the new born child requires the aid of the mother; its lungs, which 

 are delicate and imperfectly evolved, do not supply a due quantity of oxy- 

 gen to the blood which circulates through them : the animal heat would 

 be under what is required by the wants of life, if the mother did not make 

 up for this deficiency, by transmitting some of her own warmth. She 

 folds her infant gently to her bosom, warms it with her breath, and by 

 this kind of maternal incubation continues to cherish it with that calori- 

 fic influence to which it was fully exposed, while forming a part of her- 

 self. Besides, she feels for it, keeps it from danger, foresees its wants, 

 and understands its language ; and this very interesting intercourse takes 



* See the Chapter, at the end of the APPENDIX, on the Chemical Constitution of the 

 Secretions. 

 f Lac est dbus exacts con/ectus. Galenus DeUsu partium. Lib. VII. cap. XXU= 



