There are vegetables, of which the onion and turnip are good examples, that contain ingredients that find their way unaltered into the milk. So long as these do not disturb the mother their presence has no unfavorable influence upon the child. Similarly a number of substances appear in the milk when administered as medicine to the mother. In one way this is fortunate, for under certain circumstances it provides a very satisfactory method of treating unhealthy children without giving the medicine directly. In another respect, however, it is a disadvantage, for it sometimes interferes with giving the mother purgatives, which she may need. So far as possible, therefore, the taking of medicine should be limited during lactation, and certainly no drug should be employed without the advice of a physician. Time and again some drug, some beverage, usually one that contains alcohol, or some special article of food has been recommended as a means of increasing an inadequate secretion of milk, but thus far all attempts in this direction have failed of general application. There are at present on the market widely advertised preparations for which astounding efficiency is claimed. None of them, however, has a definite or consistent value; and it is unfortunately true that no substance has yet been discovered that has the specific action of increasing the production of milk. _Psychic Influence_.--Although the nerves of the breast which regulate the secretion of milk do their work whether the mother wills it or not, her state of mind has an influence over the process, just as it has over digestion. No one doubts that our minds influence our digestions as has been so clearly proved by the skillful experiments of Pawlow, an eminent Russian physiologist. Cheerfulness promotes perfect assimilation of the food, whereas mental depression decreases the secretion of the digestive juices or checks them altogether. In a similar way, perhaps, we shall some day have explained to us the unquestioned fact that mothers who maintain a happy disposition nurse their babies efficiently, while those who are inclined to worry often experience real or imaginary troubles with lactation. The most striking manifestations of such psychic influences are those in which, as a result of some strong passion or deep sorrow, the secretion of milk suddenly ceases altogether. Fortunately such effects occur rarely and are never permanent. After a few hours at most the secretion is reestablished; and if there are alterations in the quality of the milk, these will correct themselves just as quickly.