The bones are still soft, the tender flesh and skin with little or no power of resistance.

Muscles, nerves, all the wonderful tissues, are in process of formation; and in the strange growth and development of this most helpless yet most precious of all God's creations, there are certain elements which must be had,--phosphates to harden the delicate bones; nitrogen for flesh, which is only developed muscle; carbon,--or sugar and fat, which represent carbon,--for the whole wonderful course of respiration and circulation.
Water, too, must be in abundance to fill the tiny stomach, which in the beginning can hold but a spoonful; and to float the blood-corpuscles through the winding channels whose mysteries, even now, no man has fully penetrated.

Caseine, which is the solid, nourishing, cheesy part of milk, and abounds in nitrogen, is also needed; and all the salts and alkalies that we have found to be necessary in forming perfect blood.

Let us see if milk will meet these wants.
COMPOSITION OF COW'S MILK.
(_Supposed to contain 1,000 parts._) Water 870.2 Caseine 44.8 Butter 31.3 Sugar 47.7 -- ---- _Carried forward_ 994.0 _Brought forward_ 994.0 Soda } Chloride of sodium and potassium} Phosphate of soda and potassa } Phosphate of lime } 6.0 Magnesia } Iron } Alkaline carbonates } -- ----- 1,000.0 Mother's milk being nearly the same, having only a larger proportion of water, will for the first year of our baby's life meet every demand the system can make.

Even the first teeth are no sign, as ignorant mothers believe, that the stomach calls for stronger food.