When the child is born the best nutriment for the baby is the milk of its mother, and if the mother be not available for this purpose, a wet nurse must be obtained, for human milk is indispensable in the nourishment of the baby if we desire to influence its future immunity against infections; for this important purpose all the internal secretions of the ductless glands go into the child through the milk which contains them. Sajous holds that millions of infants die solely because they are deprived of what nature provided for them, the maternal milk, which not only nourishes them, but protects them against disease. The infant is practically helpless against infections, for its thyroid contains scarcely any colloid substance, sometimes none; and it also contains no iodine,[167] especially in children who are descended from parents suffering from chronic cachectic diseases, such as tuberculosis, syphilis, malaria, insanity, etc. The other glands are also not yet sufficiently developed, as this takes place generally in the years toward puberty. Footnote 167: Baumann: “Zeitschrift für Physiolog. Chemie,” 21, 319, 1895; 22, 1, 1896. All the internal secretions will, therefore, come to the children from the mother or wet nurse. The above fact also explains why infectious diseases are so very frequent among infants, and also among children before the years of puberty. The avoidance of infectious diseases is especially important for infants, for in later life many other infections will occur preferably in those children whose ductless glands have been weakened by previous infection. Therefore, even with adults, when we take the history of a case we should inquire whether, in childhood or later, the patient has suffered from infectious diseases. The necessity of such a procedure will be more clear after we have shown their relationship with a weakening of the ductless glands. The possibility of premature old age is greater in a person who has suffered from one or several infectious diseases in childhood than in another who did not contract any. Very interesting experiments have been made on puppies fed on their mothers’ milk, and some with raw and boiled cows’ milk, showing the superiority of the bitches’ milk, and also of the unboiled milk. When human milk is not available for divers reasons, fresh cow’s milk should be employed, using it raw, however, in order not to destroy, by boiling, various substances of the nature of ferments. Before giving it to the baby, the cow’s milk should be diluted with water, and milk-sugar and cream should be added to make it more like human milk (see Chapter on “Milk Diet”). Of course, when giving raw milk, we must ascertain that it comes from cows examined specially for tuberculosis, and that the milk is of the best quality and very fresh since it has been shown that its power to kill bacteria—and therefore to protect the child—begins to decrease soon after it is drawn.