_The secretion of milk may be entirely stopped_ by the action of the nervous system. Fear, excited on account of the child which is sick or exposed to accident, will check the flow of milk, which will not return until the little one is restored in safety to the mother's arms. Apprehension felt in regard to a drunken husband, has been known to arrest the supply of this fluid. On the other hand, the secretion is often augmented, as every mother knows, by the _sight_ of the child, nay, even by the _thought_ of him, causing a sudden rush of blood to the breast known to nurses as the _draught_. Indeed a strong desire to furnish milk, together with the application of the child to the breast, has been effectual in bringing about its secretion in young girls, old women, and even men. Sir Astley Cooper states that 'those passions which are generally sources of pleasure, and which when moderately indulged are conducive to health, will, when carried to excess, alter, and even entirely check the secretion of milk.' But the fact which it is most important to know is, that _nervous agitation may so alter the quality of the milk as to make it poisonous_. A fretful temper, fits of anger, grief, anxiety of mind, fear, and sudden terror, not only lessen the quantity of the milk, but render it thin and unhealthful, inducing disturbances of the child's bowels, diarrhœa, griping, and fever. Intense mental emotion may even so alter the milk as to cause the death of the child. A physician states, in the _Lancet_, that, having removed a small tumour from behind the ear of a mother, all went on well until she fell into a violent passion. The child being suckled soon afterwards, it died in convulsions. Professor Carpenter records in his Physiology two other fatal instances: in one, the infant put to the breast immediately after the receipt of distressing news by the mother, died in her arms in the presence of the messenger of the ill-tidings; in the other, the infant was seized with convulsions on the right side and paralysis on the left, on sucking directly after the mother had met with an agitating occurrence. Another case of similar character may be mentioned. A woman while nursing became violently excited on account of a loss she had just met with from a theft. She gave her child the breast while in an intense passion. The child first refused, but ultimately took it, when severe vomiting occurred. In the course of some hours the child took the other breast, was attacked at once with violent convulsions, and died in spite of all that could be done for it.